I am really sorry to see what has happened to you, particularly just four months into a marriage. You are really going through the mill, and it is always hard to go from the mindset of being in love to the mindset of separating for your own long-term well-being (which is what quite a number of people here are suggesting). However, some of the things she is saying to you display a worrying capacity for manipulation and blame-shifting.
“She mentioned that she was disappointed that I wasn't giving our relationship another chance.”
Is she nuts? It’s four months into your marriage and she cheated. That’s grounds for disappointment. You are the innocent party here. You’ve barely brushed the confetti off your best suit and you are already being expected to reconcile after her infidelity, or risk her disappointment.
“And honestly, I never thought of it like that.”
No, because you were using common sense, logic, and a sound grasp of the truth. For her to find ‘disappointment’ in your actions is self-serving manipulation, and unfortunately, it seems to be working on you. You mentioned that she had studied psychology. Do you think she is using it on you? She cheated less than four months into your marriage, and she’s got you thinking you’re the bad guy? Wow, she really knows how to apply her psychological training. It’s like those poor battered wives who make excuses for the husbands who clobber them: “It’s my fault, I keep letting him down and making him mad. I should be a better person, he has a lot to put with”.
“She has told me that she genuinely just wants me to be happy”.
Well, she does understand happiness. Her own. She announced in the counselling session – without even being asked, which was a nice touch – that she had been very happy with the guy she cheated with, and had a nice time. She seems to be upset that you aren’t sharing in the happiness, but of course, we have already established that you are the disappointing bad guy who fails to appreciate the efforts his wife makes to keep him happy.
Sorry, I apologise for being harsh in what I’m saying, but honestly, she is just manipulating you here. You are the victim here, not the perpetrator.
“When she was packing everything up and we were going through who gets what, she broke down at anything that reminded her of all the good times we had together.”
I remember talking with a long-term girlfriend many years ago, and she mentioned a time when she had really upset an old boyfriend. In the course of the discussion, she said, “I apologised, I said I would never do it again, I said I would make things right, I tried crying, but nothing worked”.
At which point I said, “You ‘tried’ crying? So, you weren’t really crying, you were using crying to stop him being mad at you?”
“Yes, of course”, said my girlfriend. And I thought, “Well, I’ll watch out for that one in future”.
You and I may only cry when we are upset, but some people use tears as a tool.
“I am truthfully starting to think that the good times were so good that they outweigh what she did. The good memories are so good that it makes me not even care if she were to cheat on me again.”
I know you are in a very emotional state, but you will be setting yourself up for a lifetime as a doormat if you show her that she can do whatever she likes and you will forgive her. Never never never reward bad behaviour. You are not a doormat, you have value and worth in yourself, and no-one who truly loves or loved you would put you in a position where you have to give them an open license to behave as badly as they like. Could you really face a life of spending night after night alone at home while she is out ‘partying’ with other men? What kind of life would that be, and why – if she feels anything approaching ‘love’ for you – would she expect that of you? Would you ask the same of her?
You must not set yourself up to be the fall guy in an abusive relationship, and that seems to be the way this is going.