Well, get on top. But don’t choke him when you orgasm. Unless you are both into that sort of thing.

So just tell him not to rest his entire weight on you. It really is quite simple.

So have sex while on top of him or beside him or him sitting up, etc...

Having sex is like doing fractions, where it's improper for the larger one to be on top...

Why don't you just take control and be on top?

Lots of other positions and it’s important to communicate if you want both of you to have a good sex life together. I have quite a few pain conditions. And endometriosis. It can be painful and depending on what’s flaring, my needs to not have pain change. When I was young, I was too shy to speak up and avoided due to pain. Then we started talking about how the pain made it unpleasant and worked together to fix it. Speak up. You don’t have to say he’s squishing you. You can just say that the position is uncomfortable for you.

Top him ! What else ?