Why Can’t I Orgasm??

I am starting to become endlessly frustrated, because I can’t finish for the life of me. I’d like to start by saying (even if it’s tmi) that my boyfriend is great at making me feel good. He’s the first person to ever eat me out, and every time so far it’s been great. And when he uses just his hands, my legs will literally be shaking and the feeling is so overwhelming that I have to tell him to stop sometimes because it’s too much to handle.

I’ve tried sticking it out, even when it’s overwhelming hoping that I’d be able to finish, but nothing!!!! No matter how hard he tries or how relaxed I try to keep myself, I just can’t seem to finish for some reason. I feel bad because I don’t want him to think he’s doing anything wrong. Is there a reason why I’m like this, or is it something either of us are doing incorrectly?