I'm a bad husband

Me and my wife split up almost a year ago. We had a lot of issues during her pregnancy with fighting and it got worse after. She was diagnosed with postpartum depression. But she didn't want to get help. She didn't believe in medication really. And she said therapy is stupid. Plz understand when I say I tried because because I get her body wen through a lot but how much more can you try when they don't want to get help. She would start fights for dumb reasons and gaslight me. Finally I said I was done and left. I see my son every Wednesday, Thursday and every other weekend. We both used glow baby to track our sons development and since we weren't really talking to each other we would just see the mild stones on there. I moved in and got a roommate and honestlty, weekends I wasn't with my kid I was out partying with him. Then we got drunk and had sex. We both agreed to never talk about it and it was a one time thing. Then it became a two time thing, and three and four, and then when we were sober. I never really questioned if I was bisexual until I met him. We never actually had an official relationship. A month ago my wife wanted to talk to me and apologized for everything and said she's on medication now and wants our family together. I felt my son deserved to live in a two parent home so I told my friend/roommate and he said whatever makes me happy and he cares and loves me but he wants me to be happy. We've been back together a month and my wife has kind of changed and I care for her but I love him too and feel like a bad husband...

Edit: Ig idk if I still love her. I know I love her I'm just not sure if it's in the same way anymore. I just feel like I would have to be a terrible person to throw away 7 years for someone I've known one year. Especially since she is changing. I guess I'm confused

Edit2: I never felt obligated to tell her who I was in a situationship with because she had 2 other boyfriends after we separated and flashed them on social media. I kept things more private