Wanting my ADHD ex fiancée back.

Recently my fiancee and I have broken up. I want to win her back. She had started to see another man in the middle of the night. She said she liked to be around him and insisted it was nothing more then a friendship. I eventually let my insecurities get the best of me and would overwhelm her asking questions and wondering why her tone was the same as when we first fell in love. The last time we were around each other we had a date and it went well. We had some drinks and I fell asleep. I woke later in the night to find her gone. Her Xbox chat was still on and me hearing her voice with the other man. I listened and eventually blew up her phone because I was worried after she had drinks and was afraid he'd take advantage of her. A lot more happened but eventually I decided to move out the next day. I needed to set my boundaries. I still pay for everything in the apartment but I'm afraid she'll never get back with me now and that she's moved in to this new guy. All because I've overwhelmed her constantly and forgot about her adhd and bpd. I drove her into his arms and I know everyday they are around each other till about 2 am which frustrates me and sometimes I want to take back my apartment and tell her to just move in with this guy. She won't change my name in her phone from husband, which I think she may have just forgot. She also doesn't want to take me out her instagram bio because she doesn't want people asking questions. I know how easy out of sight out of mind is for her and it worries me because she sees this new guy everyday until late nights. I want to believe it's just her being able to talk and have some understanding. And believe it's just friends but I also know that after that night she craved his touch. I heard the words come out of her mouth. It's been able two weeks and I've really tried coping and just don't know how to win her back. Please help.