My gf [F23] left me [M23] left me and I was completely blindsided. Was it my fault and do I deserve it?

My now ex left me last night after being together for over a year. We had gone through so much together, starting our careers and planning on moving out together. We had split up for a month after I had hidden stuff from her (contemplated using PEDs and wasn’t honest with her about it). We split and it killed me. I began to work on myself and went to therapy and we ended up getting back together. Things were weird at first and I had to prove to her she could trust me. I gave it my all, 100% to be a better partner, she had always said I was so supportive and had been great at listening and providing reassurance to her and helped her with issues related to past trauma.

Being honest I’m quite a closed off person regarding head space and processing my thoughts. I was abused as a child until I moved out at 16 and had never had a real home until I met her. I showed her the darkest parts of me. And we both (or supposedly) wanted a life together.

Fast forward to yesterday, we had a open conversation about her needing me to be more open and that’s why she was being distant and cold with me recently (she never said this prior even after me asking if it is me and what I can’t do to support her at this time). I vowed to try and be more open and regularly check in with her regarding where my head is at (I need set routine as I’m autistic). Things seemed okay and she said that she didn’t want to leave. The next day we had such a loving and wholesome day, going to shops to look at things we’d get for our place when we move out and cooked dinner together and sat down to watch a film.

About halfway through the movie I could sense she wasn’t okay so I gently asked if she was feeling okay or wanted to talk about her headspace. She then told me she had decided at the start of the week that she was gunna end things because she couldn’t see a future with me and she feels we are using each other for an escape. I tried to discuss it with her, to understand where she was coming from and how I felt about it all but her mind was set. She’s now gone no contact with me. I’m angered and hurt but most of all I’m so incredibly sad. She was my person, twin flame and now I’m a stranger.

She has now in less than 24 hours followed the guys she wanted to fuck while we were separated after telling me it was just because she was lonely. I’m so hurt and angry and just want to do the same but I don’t have it in me