How do I tell my boyfriend I’m bi?

Okay so I’ve had a boyfriend for over a year now and I still haven’t told him I’m bi. He said if he ever found out I was gay he would be really upset so I’m kinda not wanting to tell him. He is super conservative and he isn’t really that accepting. I really love him, but I feel like he doesn’t know a big part of me. What should I do?

Update: I told him and he completely accepted me. He said he would love me no matter what and I should’ve told him sooner.