Why is it the only think I think about?????????? How can I convince myself it isn’t true when it feels so real??????

Does anyone else experience a moment of clarity where you feel strong relief that the intrusive thought isn’t true, only to then immediately start questioning if you’ve only convinced yourself that because you don’t want the thought to be true? I’m pretty confident it would take some crazy mental gymnastics to actually successfully convince myself I didn’t do something that I deep down knew I did, but every time I resist the compulsions and try to sit with the uncertainty or tell myself to think about what is logical, I usually briefly know that this probably didn’t happen but am unable to move on out of fear I’m just in denial and have convinced myself of that.

Ii spoke w my bf this weekend and he mentioned that he has thoughts just like me, but his don't bother him like me. I then felt a lot better and he tried dissecting one of his thoughts like I usually do and realized it felt more real for him after. That made me realize that none of my thoughts were ever true and I blew them up. However, yesterday I had a thought ab “wait wut if you liked that one guy? How dare you bc youre supposed to love your bf and not secretly like someone else” and treated it as I usually did bc I accidentally wanted to see if it was true but didn't rlly but I would check to see if it was there and now that thought feels so so so real now and I feel really bad how do Ik it's not real? I feel so bad and guilty bc lividly this makes 0 sense but it feels so prominent. It felt pretty real when it happened yesterday too. And now I feel awful bc how is it possible after my clarity the other day? Why does it feel so prominent 😞😞😞

Is ocd supposed to feel like a genuine belief ? I see or hear some people saying things like « I know it’s not true but …. » while I personally don’t « know that it’s not true » I feels genuinely real and I even find evidence for it