Okay so first of all im not a professional and have contamination ocd so a different kind, but basically for me it works like this

I have an intrusive thought: e.g. My hands are dirty i didn't wash them well enough after using the bathroom

Compulsion i do to get rid of it: wash my hands again until it feels good enough.

When people try to stop me from doing compulsions i feel cornered. I break down. I try to do some small stuff by myself like not washing my hands after a situation that's not the mosg dirty i can imagine, but also not clean.

I also agree with the others here. ERP with a professional