I don’t know what to do...

So my SO and I have very different sex drives. I want it pretty much always and he has never initiated sex in the year and a half we’ve been together. Anyway it’s very difficult for me to cum from sex so after he finishes I always tell him to come back and help finish me off. He almost always complains. It’s just really frustrating because not only do I not get the amount of sex I want, but when I do have sex he complains about it and makes me feel bad about myself. I don’t know what to do. I’ve told him this and then he gets mad and says he’s tired after and he doesn’t want to deal with it. It just feels so unfair. Advice?