Is there anything I can do to be less paranoid about my boyfriend cheating?

I’ve been with my boyfriend for a year and a half, as far as I know he has never cheated on me and I have never cheated on him.
BUT, I guess i’m really insecure or something and I get very very paranoid whenever he goes out drinking and partying.
I think I have a right to be paranoid, but is there anything I can do to help our situation? I’m not sure if i trust him.
I want to trust him fully.

Helsinki