ADHD and Infidelity

Since reading Dr Orlov's wonderful book, I've been working hard to alter my behavior and not nag and criticize the way that I'd become accustomed to doing about all the weird things my partner does that never seemed to change. It's been a challenge but has been very rewarding to know that there is something I can do besides stay after her for her neglect of me, her forgetting things constantly and many other small things that go on and on. Things initially got better and we were discussing finding a therapist for her. We also argued far less, not much at all. Then things worsened again. I thought I was actually getting better at not nagging and talking about problems differently, offering encouragement when things went well. I became discouraged. Turns out, she has been building a romance with a co-worker where there is kissing, sexting and negative talk about me (that he is just fine with if it gets him closer to getting laid I would presume). She told me about the situation after lying about it several times. It started off as a crush and after it got more serious, she stopped talking about it and I discovered by asking questions.

I don't know where to go with things now. We are an interracial couple, I'm Black and she's white. My family loves her but they are also old school and will likely not be very impressed if our family dissolves because she's fucking around. I don't want our son to grow up with it impressed upon him that his white mother broke up the family by cheating. This detail isn't about ADHD, I know, but I'm trying to give an idea of the pressure I'm under. I love her and want to make it work but don't know which way to go at this point. She doesn't show remorse that seems sincere and that makes me feel like there is no way to fix this. Thanks in advance to any encouragement, advice or support offered this is a great community filled with wonderful people that I'm proud to be among.