HOW TO ORGASM???!?!

My boyfriend and I have been having sex throughout our relationship but I have never once orgasmed. There's been moments where I feel like I have to pee but it won't ever come out no matter how long he keeps going in that position! Im getting extremely frustrated because I know he gets concious about not being good enough to make me orgasm. Even if he focuses on me the whole hour I just can't seem to. Please any detailed tips would be greatly appreciated.