Hello Outsider90,
that sounds sad and very frustrating for you. I am sorry you're going through this. I do know that the research indicates that there are lots of sexless marriages for all sorts of reasons. Not that that solves your problem but possibly helpful to know that you are not alone.
Have you two been able to have a calm and loving talk about the sex issue?
I hear what you're saying. People tend to get very reductive about these problems ("oh he must be cheating on you" or "men constantly want sex") when those are not actually true. If you take a look at some articles on Psychology Today and elsewhere you'll see that there are a lot of stereotypes about male sexuality which aren't based in reality.
What about speaking with a sex therapist? Would you be open to that? Would he? If he isn't open to it, you could certainly go on your own to get some ideas.
I hope you can find support and solutions. Sex is very important for relationships unless of course both parties agree that they do not want it. Which does not sound like your situation.
Peace to you