I need help..

I have real bad anexty and I just think the worst. I trust him but I'm afraid he will just move on. Find some women with nice ass/funnier/career and move on.. I've brought this up to him and he always resures me nothing like that will happen.

How can I get these thoughts out of my head. I've went driving while thinking about the worst. To point I'm yelling at myself to stop thinking this shit.