Thank you for all your replies!
Lurkingsoul12:
Also, sex is not the only thing you should be focusing on. You should focus on everything she did from the day she developed crush on him till the dday. Every decisions, every lies, every excuses she gave to you and herself are betrayals. Focus on them too. They are as worse as sex.
You're right, I tend to zoom in on one part or another of the whole picture of infidelity. Sometimes it's the sex, sometimes it's the lies, sometimes it's the lack of remorse and compartmentalization, sometimes it's how easily she could lie and justify things to herself. It feels easier to work through each of these individually, the whole picture is overwhelming.
Potentialforevil:
Look at it this way - she went back to him and it made no sense, there was nothing. She went back to you ~10000 times and still wants to. This is special on a whole different level.
This is a positive spin. I know there were lies in our relationship, she's never been very forthcoming and hid big parts of herself from me. However, there has been genuine love, care, and intimacy. We built a great and unique life for ourselves. If she has half a brain/heart at all she can see what she gained through chasing validation was not worth what she stands to lose. She's always been special to me, but given how she acted before full disclosure, it's hard to believe we were special to her. Maybe she sees it now?
Bigger:
You pose a good point. The betrayal happened. Do the details really matter? When thinking about D, I think the answer is no. She chose to chase a short term high to 'fix' her brokenness at the cost of hurting me beyond comprehension. When thinking about R, I can't help but try to find the things that still remain exclusive between the two of us. Maybe I'm trying to find something to hold onto that redeems an effort to R. Maybe I'm just pain shopping.
HellFire:
Your jealousy was because your gut was telling you she couldn't be trusted.
I think this is partially true. My retroactive jealousy had been an issue for a long time prior to these events. Only the year prior to these events did I do something to change, did change, and became a better partner. I tried to patch things up and apologize, but she rug swept and was probably already checked out. I don't doubt she was going through some trauma response to how I had previously treated her. I'm not making excuses for her, just trying to acknowledge how I damaged her and the relationship. Maybe the whole time the jealousy was telling me something about her. Maybe she would have always cheated and was never trustworthy, she certainly has several vulnerabilities to cheating. But, maybe my issues broke her and gave her that tiny push over the edge. It certainly made her justifying things to herself much easier.
sisoon:
If you believe your W is generally honest, my bet is that she's honest about the sex, too. If your difficulty believing her is a sign of general disbelief, you've got a big red flag you need to resolve.
At this point, I do believe she's generally honest, but she has a long history of lying about things that might upset or disappoint me. Last night she broke down crying, confessing to me she told a white lie at work. I think she's very disappointed and ashamed of herself and is committed to fundamentally changing herself as much as she possibly can. I do still have a lot of difficulty believing her since I've been lied to so much over the years. She has been able to look me in the face so many times and tell me what I wanted to hear. It's not a comfortable position to be in.
Shirley Glass described a stage for people who didn't quite know what they wanted that she called 'working on the M' - you act as if you're going to R and see how it works out.
Not Just Friends was the first thing I picked up one week after I started to address my suspicions. Ideally, this would be my course of action. Stay living together and see how things go. However, we're in a complicated living situation. We live out in the middle of nowhere with several roommates, all in one big house. This is not a conducive environment for doing serious work on our relationship. It's difficult to be going through the worst time of my life and have to pretend every day that we're fine. It's isolating. I feel like I need to expand my social network and engage in life on my own terms, with less compromises. I'm afraid this separation will sabotage the communication and work we've been doing so far, but I know we both need to sort ourselves out before I can make a decision and before we can address the relationship. Many days I wish she was moving with me, but I know I'm not closing any doors and need to break out of codependency. I just hope I can feel more confident one way or another in six month's time.