Is it even possible for her to come back?

I broke up with my fiance about a week ago. We have consistently had issues, but she had JUST started receiving treatment. Just the same day she told me I'm the love of her life, how much she misses me, etc. I broke up with her and made sure to highlight it wasn't because I didn't love her and that I wanted to be with anyone else, but rather because she wasn't being a good partner to me.

In retrospect, while this definitely was true, I wasn't being a good partner to her either. I was dealing with a lot of stress and irritability from other parts of my life, as well as her consistently splitting, and general low mood.

I had broken up with her before, but this was the only time I broke up with her when we weren't face to face, which I did specifically because she wouldn't let me end things in the past (would threaten me in various ways). She was physically apart from me, a different state, and I also blocked her everywhere after sending the text.

Soon after this, she moved on (within hours), and found someone else to be intimate with. She also supposedly stayed up all night not that night, but the one after, discussing how much she cares about me with her friend, or at the very least discussing how much our relationship meant to her.

I was not in contact with her directly, but instead her friends. This was because I needed to coordinate her getting all her stuff as well as addressing her shared pet (we were living together).

Just a few hours after beginning NC/sending the breakup text, I was already experiencing profound sadness and withdrawals. This continued and got significantly worse in the following days. By day 4, I was miserable.

I made several huge mistakes. First, I logged into her social media on my phone (we shared eachothers logins) and I found videos of her being intimate with other men the same night I broke up with her. From this I began having a panic attack, and drove to her work to ask her how she could kove on from me so quickly. She wasn't there, and I left and went home.

She of course found out I went to her work and logged into her social media, was embarassed and incredibly upset, and although I didn't know her feelings towards me before this (possibly equally upset), she was very, very upset afterwards and didn't want anyone communicating with me under any circumstances.

Its been a few days since then, and her opinion has not changed. She will not see me for closure and has me blocked everywhere. So total time since I've broken up with her is about 6 days exactly.

Obviously I have done several things that are absolutely wrong. I also ended things with her. We have gone through similar and worse levels of drama before, with both of us propagating it. We were together for 2-2.5 years, engaged, and lived together and were very, very close. We were also eachother's first serious relationship, and first adult relationship.

My question is:

Is it even possible she comes back? Do people go back to their FP after things like this? What can I do to increase the chances she comes back (besides going to therapy which i have started, working on my outside stressors and factors of irritability)? Is it more likely though that she will move on because I ended things, she's split black towards me, and now she feels social shame about going back to me? And finally is it possible that she comes back but not with the intent of an actual long lasting relationship? Keep in mind she has just begun treatment, and assuming she sticks with it that may affect things (mood stabilizers and weekly DBT).

I know everyone will comment "move on" and I absolutely am trying to. That is my #1 priority at the moment. But please indulge me. I can't see myself with anyone but her, and I just want to know right now.