You described a woman in love, but unfortunately with another man.
I can really feel your pain and desperation. I've been there too, not as a husband but as a BF deeply in love. You see her drifting apart from you, if you take an action to prevent this, she makes you feel like you are boring and overwhelming her, if you don't do something and give her a space, she continues to move away from you and approach the other man. There is nothing you can do.
She indicated that she had been "trying and putting in effort" for the past year and felt like i was the one who wasn't doing anything and now she's kinda burnt out?
Did she give concrete examples of her trial and effort or did she just say it? If you didn't think she was right, you should have objected rather than apologized. She probably does blameshifting and gaslihting. She's trying to make it look like you're the problem.
As others have said, the amount of time they spend together, both on and off the job, is excessive, and this creates a lot of opportunity for PA. It would be too optimistic to think that they are not taking advantage of these opportunities. Even if, miraculously, PA has not yet occurred, it is clear that everything goes in that direction. Frankly, they don't even feel the need to hide it, they are dating right in front of you.
This all makes me feel super uneasy and hurt. My wife doesn't do any of this with me. In fact it seems like a chore to her to have to spend time with me. But she willingly and gleefully seems to adore being around this guy
Have you ever asked her what they were talking about in all this time? What are the things that she is so eager to share with him but not with you. You're right about feeling like a sıuperfluity. She may see your presence as an obstacle to spending more time with him.
After I told my wife that I was uncomfortable with her and Mark being together so much and their "friendship" or whatever it is, I felt very strongly that I shouldn't tell her what to do or anything.
This is actually what it should be. I also feel uncomfortable when someone does something just because I say it. I hope they notice the discomfort I'm feeling and give up what they're doing because they care about me.
However, your wife doesn't care about hurting you even though you have expressed your feelings and she continues what she does.
As I said at the beginning, you may be too late to get her back. Yes, I say "back" because right now it looks like her heart belongs to him. In case of making a choice, she may choose him. You are newly married and there is not much that binds you apart from your vows. And AP is also a free single man.
All this does not mean that you turn a blind eye to what is happening and accept it. You should stop nice her back and doing pick me dance. You have to stand up for yourself and say that her behavior is disrespectful and unacceptable to you. Yes, you can't control her and forbid doing things, but you can say she can do whatever she wants but not as your wife and you are out.
For now, even the things she's apparently doing are beyond the boundaries of a marriage, and she's well aware of it. Your over-understanding encourages her.
As others here say, gather as much evidence as you can before confronting her; messages, videos, PI, phone bills, credit card expenses, VAR etc... Because you do the same job, maybe you have a friend who has friend at their office. You can also get information from him/her. Their A may not be so secret for their coworkers.
You don't need any of that to break up with her after all, her attitude and how she makes you feel are enough. But you seem so in love with her and your intention seems to be R. Maybe you will change your mind when you know the whole truth. If not, at least you know what you're R with, of course R requires two people who want it and the other one hardly seems to be there.