I feel like you are answering your own question… like you know what you need to do but just want some reassurance about it.
You know… if he would even just talk about the problem with you, well, that would be something.
But as it is, you are left just holding the bag… not knowing what to do with it.
Because you are trying to please him but he isn’t reciprocating.
What to do with that???
How can you ever feel good, free, loved, whole or anything else if your lover won’t even talk about it, much less do anything except put his penis there.
Sex like this is actually just one step from masturbation in my opinion.
no closeness, warmth, intimacy, or all the beautiful things that make sex so wonderful.

I am telling you what I would do.
I would tell him that this is unacceptable to me.
That I really love sex and want a very satisfying sex life and I am not getting it.
I would tell him that I want some time to think things through. I want to just have time to be who I am and see how I feel.
This will give you an opportunity to find out how much he means to you and what you are willing to trade off for in the relationship.
Trade offs aren’t all bad… but some are dealbreakers.
If you find out that this is then you are halfway out the door.
Best wishes.