Is she ever coming back?..

That’s my story but to summarize it all, she basically had enough of me because I “treated her like shit” when I was just jealous and demanding sometimes. The last time we talk was after she came back from the hosptial where she said she couldn’t do this anymore and needs space but still claims to love me. The reason why she went to the hosptial is because she had depression and her parents found out about it. I then contacted her 2 days straight to forgive me and take me back. After all that, she blocked me off of everything & said she will never get back with me I treated her badly and just had enough of everything. I also came back from the hospital from having an anxiety attack because I recently found out a week later she’s already taking to someone and from what I saw which was a guy running out of her house, that she slept with him already.

Now it’s been the 22nd day of no contact and I have been taking therapy everyday and honestly I feel better. Since I have friends on social networks, I see her being with friends with people she hated and told me not to talk to. Which confuses me because how can she immiedietaly be friends with them when she doesn’t like them. She’s been happy lately and doesn’t seem like this breakup didn’t mean much to her. It’s been 3 years and 4 months that we lasted. Last year around the exact same thing the same thing happened in which she left me for the same reason, dated another guy, and then she came back. But I have a huge feeling this time is different to her and she might think twice before she’ll want to talk to me. I don’t know if The letter would make a difference because her parents hate me and if I even get near her, her brother, which goes to the same school, sees her everywhere she goes. She always had issues of liking bunch of guys in the relationship. So idk if she’ll ever come back or anything?
Any advices or feedback is appreciated.