I’m so scared my partner is cheating on me. I just want to give up :(

Finally my partner decided to break up with me, and I feel totally empty. He wants an open relationship, which I can’t handle. Just feel broken inside 💔

For some time i was obsessing over relationship with my girlfriend. For a long time we we're each other's best friends and we only had each other. Recently she made a good friend in work and im obviously really happy for her because she deserves to be loved by more people than me. But i started to feel really jealous. I never thought she can cheat on me i just have really low self esteem and i started to obsess over if she is still in love with me or if she is still attracted to me bc she sometimes would be more interested to spend time with that friend and not me. We talked about it a lot and i tried my best to not be jealous and give her space but i felt how she's distancing from me. At some point she stopped showing me her love in any way. She stopped hugging me and kissing me and she kinda stop telling me she loves me. She only responded "me too" when i told her i love her. I talked about it with her few times and she always said she understands and that she's tired and don't really need physical touch etc. But i was still worrying bc i just knew something is off. She really was acting different. And then few days ago she told me she's actually tired not because of job but me. She feels irritated by me and she don't know why and that she actually thought about breaking up with me and she don't know what to do because she's confused about her own feelings. She said she thinks she still loves me but it's hard for her to see a difference between friendship and love and that she feels tired of concept of dating someone. She said we should wait and see bc she thinks she still loves me but i don't know if that's honest. I don't know what to do anymore im crying all the time every day since that conversation we had. I feel like my worst nightmare just came true and now it's real and not only a though in my head. I can't do anything and i feel like it's the end of the world. We're living together and i don't want to go back to my parents but that's not the worst thing. I just love her so much and i can't hande thought of loosing her. My ocd made me question every single thing about me but somehow i never questioned my love for her so that's why I'm so emotional about it. I don't want to lose her. I don't know what to do i just want to be loved but I don't want anyone else. I don't know what to do im so scared. I want to die every time i look at her with love in my heart and i know she doesn't think about me like that anymore.

I am so deeply terrified of the possibility that I could be emotionally cheating on my partner. This obsession has dominated my psyche for 6 months now, and even though I have told my partner about my crush, told him about my fantasies, told him about my fear of emotional cheating, and done everything in my power to eliminate ANY sort of closeness with this person in a group setting (including keeping them at arm’s length, acting aloof, ignoring them, ensuring that I’m never alone with them, ensuring that I never initiate conversation with them EVER even in group settings, even obsessively monitoring how often I reply to other people in a group server), the guilt still doesn’t stop. I feel like i’m going crazy. I’m googling “emotional cheating definition” like every single day and trying to figure out if having a crush counts (even though my partner knows and says it’s okay).