It's funny, but there was a time when I came on here considering whether or not I was a narcissist.
It turns out that what my true problem was numbing my feelings to the extent that I couldn't really feel much of anything. That meant also that my ability to empathize was about nilch. I think you need to continue in therapy, and I don't think it's easy as fooling someone into believing you are normal.
There are a couple of things here, Zug has pointed some of them out, that I identify with and can therefore share my experiences.
H and I also did some swinging early in our relationship. This was 20+ years ago. I tried to like it but I did not. Despite the fact that I did cheat on my husband, I believe I am very monogamous by nature and it was really soul crushing in many ways to keep sharing myself in that way with other people.
When I go back and put it into what I have learned it was about people pleasing as well to a certain extent. I was sexually abused growing up and I felt in order to be "cool and accepted" by men I needed to be adventurous. That isn't who I am though. I am adventurous but really with one person.
The people pleasing comes from not having enough self love and self respect to enforce my own boundaries. To protect my happiness.
And, it led very much to an identity crisis of sorts. I didn't know who I was, what made me happy, and in having the affair confused the issues a lot. I have hustled for someone's love since I was young. With my husband and kids I just over did for them all the time. To be deserving of their love being subservient and putting their needs above my own at all times was the way I believed you needed to be in order to be a good wife and a good mother. As the kids left, and my husband became busier as he started his business I was really lost, bored, lonely. I hid in being busy, working 15-18 hours a day 6 and 7 days a week. I stuffed my feelings until I was emotionally exhausted.
In therapy, she had me stop doing everything and sort my should from my coulds. She said I made everything a should. I had to closely monitor my motivations for why I was doing things. I couldn't do them to earn love, I was to remind myself I am worthy of love for who I am and not what I do. (At the time that rang hollow because I didn't like who I was, especially after having cheated on my husband. I do not envy where you are at - I am just telling you this because there is hope. Also to illustrate how people pleasing becomes toxic, it creates resentments, that often we create our own expectations of what we should be and what we should be doing.
It's understandable that your husband does not trust you, that your hobby triggers him because you used the time as a mask to conduct your affair. It's okay that you miss it. It's not the only hobby in the world you can have though so you need to hold that question. Maybe you can still read about it and conduct online conversations in which he has your password and can monitor it. If the whole topic is triggering to him, then you really will have to find some other things to be interested in at least for now. If you guys effectively work through things there are ways you can create transparency and negotiate those things later.
In the meantime, it sounds like to me you don't really have a clear picture as to why you turn to cheating. So, it would be my recommendation to start with your whys.
I share these two because I think they are universal, but also it's where I started in mine. You then just need to build on those from the clues you found in them. Your whys are all internal to you and you alone. They will become a list of things to work on.
I felt entitled to have the affair because ______. Usually this is some sort of perceived sacrifice we make or a perceived imbalance in the relationship in which we contribute more. It's a false story we tell ourselves to justify our actions.
You were seeking validation, you said that, and I think it's also super common. So, you need to look at the roots of why you don't love or respect yourself and you need someone else to prop you up. This is hard, and sometimes you have to go through all your foo...I did this one with my IC.
Read how to help your spouse heal from the affair. Read the Betrayed forums here. I don't think you have yet really connected to the destruction. Read about trauma, it will help you understand your husband more.
You do sound a bit flat, but when I was where you were I was flat too. It is the part that made me feel like a narcissist, and it was confusing.
Switch therapists and start over if you feel you tainted this one.
Also, the fact your relationship was abusive and sometimes your husband admits and denies makes me think there are still some dynamics at play. I would do some reading on codependency. It sounds like you may not know where your boundaries even are to begin to enforce them. I can relate to that as well.