How do I tell my boyfriend I can’t do oral sex?

I love my boyfriend with all of my heart. I have some rare thing that kinda happened two months ago... it was my jaw went out of place and I can’t open my mouth very big, the doctors never seen anything like that before and no one knows what to do, I can’t get surgery or anything soooo I think I will live the rest of my life with this jaw.

I’m afraid to tell my boyfriend. He knows I have this jaw problems but he thinks it’s going to get fix soon... I don’t think it will ever get fix

Basically this is kinda embarrassing but I could never put his dick in my mouth ever again because his dick is too big for my mouth

I’ve been with him for 2 years and we were always doing that but two months ago that happened to my jaw and I don’t think I’ll ever get it back to place

I’m afraid he’s going to leave me

How do I tell him this

Or should I break up with him so he can find another girl who can please him and make him happier

That will hurt me so much because I love him but I want to do whatever makes him happy