Help me have an orgasm!!

I’ve had sex with my boyfriend plenty of times, but only he has an orgasm. I have played with myself plenty of time but I can’t even make myself orgasm. I know what feels good and I tell him but even when I do it for 20 minutes I get nothing. I hate not getting the full pleasure of an orgasm. I’m not sure if I have to buy something for me or what? Please help!!!