Need unbiased opinions

I am really in need of outside opinions. I feel like my friends might have a biased opinion on what has happened, so I would like people to be as transparent as possible even if it is a hard pill to swallow. I will be going into great detail just to warn and would appreciate detail in how this might have something to do with my mental health and how I could possibly fix this. For the past 4 years I had been in an online abusive relationship with a schizophrenic narcissist that manipulated and pulled me into a trauma bond using gaslighting and lovebombing, then completely flipping the switch tactics. He would tell me he loved me and then tell me he would kill me and my family amongst worse things when I did things he didn’t like (like “spending too much time with my friends”), yet I always still stayed. I am diagnosed with major depressive disorder and frequently experience depressive episodes. I was a very lonely person in these years of conversing with my abuser, we would frequently have fights which would make me block him out of being overwhelmed and then he would stalk me online until I had no choice but to forgive him. He would always be there for me when I had my depressive episodes, and listened and gave me advice. But it got to a point where he knew I’d come crawling back because I had no one else, so he would just continue his possessive and abusive behaviour. He found out where I lived, hacked me (read all of my messages to others for months and never told me), sent things to my house as harassment when I blocked him, said he would come SA and kill me and all of my friends just to keep me forever locked in his house amongst other things. But there were also many highs. I was sexually involved with him, we would *** often and play games together, make jokes and tell each other we loved each other and that we would be together in real life in the future. We texted every single day, every minute we could. Called each other soulmates. This year I then met a guy in real life who I really like, we have been together for about 7 months now. I broke up with my abusive online ex a week before getting with my current boyfriend. He is perfect. He treats me with respect, lets me talk to whoever I want, kind and caring and not controlling in any way. Everything was going great and we had a beautiful time together in the first two months. I was finally getting the healthy treatment I deserved. The third month however was when I made some mistakes. I had been in contact with my ex saying that we could still be friends. That was my first mistake. But I noticed that I was still thinking about him in a different way, so I thought the right thing to do is tell my boyfriend that we should take a break. He understood and said he would give me time away to come to a decision. The next day when my boyfriend was at work I was at home and had a depressive episode. To “help” myself I started drinking, got a bit drunk and then ended up texting my ex. I ended up saying some horrible things, telling my ex that I loved him and that I wanted him back, that my current boyfriend wasn’t sexually satisfying me, borderline *** and just me losing my mind crying while texting my ex because I didn’t know what to do or what I was doing or feeling. My ex sent my current boyfriend the messages after and then came to my house, looked through the chat logs while crying. I felt absolutely horrible. He obviously broke up with me after that and I was in a deep depression for days. Eventually we were able to heal our relationship together with time but my problem is that I cannot stop feeling bad. I have cut off my ex and have not spoken to him since, it has been about 4 months since that happened but I still get massive bouts of guilt and shame. I lost my best friend who happens to be my boyfriend’s close friend when they found out what I did to him. I lost another friend as well. They sent me a message explaining how he was crying so much that he was choking, and that they lost complete respect for me. It was a big toll to take just upon losing my boyfriend in that time. This friend has only now just started to talk to me again. I feel as if they are only speaking to me and trying to be my friend again because they have to and not because they want to. I feel like my boyfriend might still not feel like he is enough even though I continuously tell him that he is, or that he may still hold a grudge. I don’t know why I said what I did, what possessed me to type those words out. I’ve told him that I’m sorry, that none of them meant anything but I took responsibility for my actions and told him that I’ll try to become a better person. I have been going to therapy, but it isn’t enough for me. I feel like I need some kind of explanation as to why I did what I did in order to truly forgive myself. There is no excuse that what I did is horrible, but what is the explanation? Being drunk and within an episode? The fact that I always went to my ex when I was in deep pain? Perhaps it had become a toxic habit? Was it my mistake to get with someone else so quickly after breaking up my last relationship? Can I even call the last one a relationship? Or was it a trauma bond? Am I just a bad person, a cheater who doesn’t understand loyalty and boundaries? Can I ever truly retrieve the friendships I had before? He did not deserve the pain I put him through, I love him very much. The feeling I get from the guilt is like that of dread, a very overwhelming and anxious feeling like there is a pit in my stomach whenever I think about it. I do cry about it sometimes as well. I don’t think I will ever forget this mistake.