How to orgasm

When I masturbate I can’t feel anything and it really sucks. I’m touching the spots I’m supposed to and where my boyfriend pointed out by when it’s me touching it I feel nothing. I don’t know how to make myself orgasm. And I have great sex with my boyfriend and he knows how to get me going but I still can’t orgasm I get filled with sensory from feeling good but how do you know when you’re going to orgasm and how do you get there