How to resist the break up urges?

I'm (24F) currently in my first relationship ever with my girlfriend (24F), we have been seeing each other for about five months, officially dating for two months. I have been diagnosed by a therapist with ROCD.

My life has been hell the past few months. It's been getting a little better with the help of therapy, but I'm still getting huge waves of break up urges. I get them multiple times a day. I might be completely fine one minute and then the next I get this overwhelming sense of anxiety and feeling trapped in this relationship which makes me want to breakup. It's like suddenly nothing else matters and I feel like the world is ending. In those moments my head sees breaking up as the only option. But I don't want to make any decisions when I am in a state like that.

After I recover from these moments, I feel incredibly guilty and scared that I'm even having these thoughts. But in the moment they feel so real. Does anyone have any tips on how to deal with these moments and not cave in?