I don't think that you are the problem, I think the problem is that the sex with your SO isn't good for you. I can't say why it's not good for you, that is up to you to find out, but that's what needs to change.

For a lot of people, it takes some effort to make your partner orgasm, or, some effort from your partner to make you orgasm, if we put it like that. Sometimes it takes some effort on your own behalf as well, mostly I think as in being able to communicate what works for you.

If you experience that he is not even trying, well, no surprise that you have to finish it off by yourself. I don't know him, I don't know why you feel like he's not trying. Maybe he's lazy, maybe he doesn't know how to please you and gave up because he feels like he's a bad lover, maybe he's selfish, I don't know. But whatever the reason is, I would focus on changing what you guys are doing so that it starts working for you. For some people, the usual dick-in-pussy is the way to go, but for a lot of people, there's just other things that need to be done. We all have our preferences.

There's nothing wrong with you because a bad (if you don't ever orgasm, I dare call it bad at this point) sex life doesn't make you orgasm. And you are most definitely not alone being in this kind of situation either. My own experience is that some guys just don't really have my orgasm as a focus, or that they just simply don't know how to make a woman orgasm. But it's also about communicating when something is not working for you, and more importantly, being able to communicate what does work for you. It's not fair to expect someone to know what to do if you haven't really told them (I don't know if you have - just talking generally here). But when you're doing it with someone else, of course it requires that that someone else is actually interested in making you orgasm in the first place, too.

I don't really have any specific advice apart from communicating with your partner about how you could improve your sex life. Try to find out what is missing for you, and communicate about it with your SO. Wish you the best of luck :) (and stop thinking there's something wrong with you!).