HOW DO I MAKE IT STOP 😭💔💔 please help me

I can’t stop thinking. I can’t stop spiraling and ruminating. I’m convinced I like this guy at work, when I see him I get scared of how I feel and practically run away/stare at him with a weird face trying to figure out how I feel. I think he’s cute and funny, and some rare times when I think about it I feel a genuine butterfly feeling but I DONT LIKE HIM. I swear to god but then it feels like I do and I avoid talking to him or anything and I’m so scared. I’ve gotten to the point of losing it and trying to physically hit the thoughts out of my head. I feel feelings sometimes around him but they’re also not real??? And I imagine him caring about me like an intrusive thought, and I was excited to hangout with him outside of work with my friends and didn’t end up going because I DONT WANT TO BE EXCITED. And this goes for other people at work sometimes too. And NO, I CANT LIKE SOMEONE ELSE. I’m trying to get back with my ex and it’s NOT okay for me to do that at all. I feel so much guilt I keep spiraling until I’m a complete mess sobbing and genuinely in physical pain. I don’t even think about him romantically unless I’m wondering about the OCD stuff. But I wondered if I would do s3xual stuff with him I actually was like that wouldn’t be horrible? And when someone says his name at work, he feels like a “different” kind of person at work than everyone else. HES NOT EVEN THAT COOL!!! IM LOSING MY MIND is this OCD?? How do I let it go for now? My ex said he doesn’t care if I like someone else right now but if I’m trying to get back with him I literally cannot let myself. Someone once tried to give me advice and said “ask him out if you like him so much!!” I DO NOT CARE TO NOR WILL I. But is that my brain trying to hide that I do??? Also for example, I imagine if I was at work and someone said “ooh do you like M?” I’d feel a butterfly feeling. But they’re not even like love butterflies but they are idk I can’t do it anymore