Welcome to SI. Before I reply to your post, I'd like to offer you a point of view which we can move forward from.
Imagine that you go to see your regular, family doctor for an annual checkup at the local hospital. You've known this doctor for years and he's always been there for you and your family, with great health care and emotional support. You recommend him to everyone you hear of looking for a new doctor. During the checkup, the Dr. looks very panicked, and he says to you, "OMG, I need to get you into the operating room right away, or you could die!" and moments later, you are being wheeled down to an operating room. It seems a little odd that a family doctor would be in the operating room, but you trust him, and so you push the thought aside as you are being anesthetized and fall asleep. A few hours later, you wake up in a tub filled with ice and in terrible pain. It turns out that the doctor actually removed several perfectly good organs from your body, sold them on the black market, and took his cute new assistant on a romantic trip overseas with the profits. Meanwhile, you are disfigured for life and will always rely on tons of drugs and trips to the hospital just to stay alive. Your life is ruined. You are also going to be broke for life from the financial impact of this. Your job, your life, your family, everything in your world is affected by this, and you feel like a fool every time you have to tell the story and people say, "Your family doctor was going to operate on you, and you said okay?" When you do see the doctor again, you say to him, "You ruined my life! I trusted you with my life and my health, and you violated everything about that! I will never be the same person again! You are a monster! You are a criminal! You are a liar and a cheat and a disgusting human being for selling my organs just so you could impress your date! I can never trust anyone ever again after this, because if my own doctor can betray me, anyone can! I can never live my life or acheive my dreams because of you. And why do you have that smug, snarky look on your face?" And the doctor replies, "Yeah, well, enough about me, let's talk about YOU and what kind of asshole you are! And let's start with you owe me an apology for calling me a monster and blaming me for you not achieving your goals..."
Given the story above, I want you to try and apply those feelings and outcomes to how your wife feels, and how she is experiencing life with you right now. In her mind, you were the one person in this whole world that was supposed to have her back, at all times, for all reasons. But instead of that, you had your own back. You abused her trust and betrayed her. To the victim of infidelity, it feels a whole lot like having your organs harvested. It is something that is done to you, by someone else, with malice, and with a complete lack of empathy or concern for your own needs and well being, for the sole purpose of the other person getting their rocks off and feeling "loved/attractive/special/powerful" somehow at your expense. Infidelity is often described as being a trauma that is WORSE than death or a violent accident. At least in those cases, while you are left emotionally or physically hurt, those things happen "despite" you, they aren't done "to you". A loved one who dies doesn't do it to hurt you or leave you alone. But when you cheat on a spouse, you are actively doing just that. Kicking them to the curb in order make yourself feel better or get what it is you need.
I just want to make it clear that my it is not my intention here to judge you in any way - we are all WS's here and we all did the very same things (and usually had the same thoughts and reactions as you are now) to our spouses and families. Rather, what I want to impart to you is a glimpse into your wife's perspective of what happened, what she experienced, and why she feels and acts the way she does. More importantly, you need to understand that this is not a "tit for tat" situation here. If things in your marriage were bad, you had options. You could have divorced or separated. You could have asked to go see a marriage counselor. You could have asked about an open marriage. Instead, you chose to ignore your own dignity, self-respect and decency. Like the doctor in the story above, you chose to do the wrong thing, and to do so at the expense of another person, one who loved, trusted, respected and relied on you. When that happens, it honestly destroys any "standing" you may have to complain about marriage issues. Your actions were a bomb that dropped and blew everything to hell.
Let me ask you... in the example story above, do you think the doctor has any right whatsoever to ask for an apology for being called a monster? Does he have any right to turn the table around and start to blame you for stuff? Would you feel any obligation whatsoever to stay with this doctor, to care about his bills or his reputation or the hardships that resulted from this, or to work with him to re-establish trust again in the future? If he too lost all his finances because of this, would that make it feel "Fair and okay" to you? Or did he bring that on himself, and his problems now are ones that he brought on himself because of his own actions and choices?
Look, your story is complex. I saw a lot in what you said. I see that there is a somewhat significant age difference between you and your spouse. It seems as if you married a woman with three kids and took on an "instant family" in the process. And you seem to indicate that there is strife between her and her kids (which I'm not sure of, simply because many WS's, myself included, tended to re-write history and parts of the story to fit their own paradigms). If so, it sounds as if you have a LOT of issues to deal with. (By the way, my story is very similar).
The problem is, the time to do that, was BEFORE. Much in the same way that, if that doctor had a beef with you, if he had brought that up with you before stealing your organs, it might have been a topic of conversation. But now? Now, all bets are off. That doctor can go fuck himself, and requires a serious attitude adjustment if he thinks you're going to give a shit about his problems now. In that same way, your wife also feels like you can go fuck yourself, and that you have some serious balls for bringing up her faults when you just won the Olympics of shittyness in her eyes. And to ask her for an apology on top of that... oooh boy. That takes some gonads, and I don't mean that in a good way. So...no, it would not be reasonable to expect nor demand an apology for the things she's said to you in anger.
What you CAN do is work on communication. It's okay to express to her that it makes you feel disrespected when she calls you names, but only in so far as expressing your feelings. In other words, "When I am called names during an argument, it makes me feel disrespected and unvalued by you, and triggers me terribly. It's okay to express your anger with me, I just request that you please tell me your feelings rather than call names" is okay to say, however, "You owe me an apology for calling me that name, and you aren't so "clean" yourself you know..." is not going to net you the results you want. Speaking of which, there is a third, and better option, which is to say something such as, "I don't blame you for calling me names, because I treated you much worse, and spoke ill of you to the AP, so I guess I deserve it. I want to understand your feelings better, so if you are willing, please tell me what thoughts come up for you when you think about what I did to you? Is there any way I can help to lessen your pain, or offer more details you need, or become someone more trustworthy?" The bottom line is, you are the abuser, she is the victim. In order to address her pain, you have to actually acknowledge it, talk about it (a lot), understand it, and empathize with her about it. She needs to be focus and it is her feelings that need to be addressed.
But what about you? Don't you get to hurt too? Don't you get to have a bad day, or get frustrated? Sure you do. The difference is, she doesn't need to hear about it. So tell us. Or tell friends or a support group. Or write it all down and then throw it in the trash. Get it out however you need to, just don't expect her to be your shoulder to cry on. The things you want to share with her are the things that you feel have helped you realize why you did what you did, and/or what steps you've taken to help mitigate further occurrences. In other words, give her reasons to give a shit.
Going back to the doctor, let's say he came to you and said, "I'm so sorry for what I did to you. I know I can never undo what I did, but I will walk through hell and back to make things as right as I can. I want you to know I've turned in my license and I am no longer working as a doctor. I've also contacted the police, turned myself in and will be arraigned soon. I've been seeing a therapist and working on figuring out why I did those things, and making sure I never, ever, hurt you or anyone else in such a way. Don't worry about the medical bills, just send those to me. If it's okay, I'd like to drop by a few times a week and help out around the house or with anything you need. Oh, and I setup a fund so that other people who face this kind of problem can be helped. I checked, I'm a compatible donor, and if you are okay with it, I can donate some of my organs to you. And I've been speaking out at conferences to help others avoid this in their lives. I know I don't deserve it, but if there is any way I can be of help, or do anything to help make things right, just ask and I will drop everything to help you. Please do not forgive me, I don't deserve it, but just know that I am determined to be a better person."
How does that sit with you? Any better than, "How about what you did to me?"
Keep coming back. We're here for you. And again, remember, this isn't meant to be a judgment of you, rather, it is me speaking from a lot of experience having walked in your very same shoes and having had the same thoughts and questions. I was a shitty WS. Let me help you to not make the same mistakes.