Can't orgasim :/

Okay me and my boyfriend have had oral and actual sex and he fingers me sometimes too and I can never orgasim?? I don't know if I can just not tell if I am or if we're doing something wrong?? Like it feels good, but it's never like amazing like I feel like the orgasim should be. Sometimes if we keep going and trying to get me to come it just starts to get uncomfortable and hurt so I just have him stop. What should we do differently to get me to come?? Is something wrong with me or something lol?? I feel bad for him too like he doesn't think he's not good at it, but it's good it's just that I never can orgasim and sometime it gets frustrating. We've tried everything that we can think of so does anyone have any new ideas that help you guys orgasim?