I honestly feel like I am a good person and that I have been a good H. I can't think of anything on my end that would have caused this. When we talked in the past and she tried to give me a reason as to this happening the it always been one of the following "I don't know", "it's not you it's me", "I wasn't ready for marriage/I was too young" or some other excuse that didn't feel like a real it was real.
Then it probably is her and not you. My point about the cheating and that you don't know how many A's she's had that you didn't catch is based on the fact you're practically newly weds and she's already doing another guy! I don' t believe a new bride would start playing around unless she's use to that sort of behavior.
I am not trying to plant ideas or upset you more than you already are, and I don't usually start telling a newcomer some thing this strong right off the bat. But you are beating yourself up & trying to figure out what you have done wrong that drove her to have an A. If she can't tell you, then that's a pretty clear sign, IMHO, that it's all on her. Believe me, if it was due to your behavior, she would be telling you all about it.
She may have more emotional needs that you haven't filled, but again, I think she would express those things when you were asking her. She doubted getting M to you! You knew she was a cheater when you M her. You probably are a fine young man who thought your love for her would change her past ways. But sometimes, the greatest loves do not change people for the better.
Anyway, I won't continue on with that kind of talk. Take care of yourself and do what you need to get through to the finals. The less you have contact with her, the better. You won't be able to talk sense into her. Talking doesn't work right now. Try not to worry about what she's going to do about filing for a D. It won't happen before your finals. First things first.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!