Can't orgasm any more

Hi, I'm an 18 year old with a lot of sexual experience but I've been having problems. My current boyfriend, my love, is the only man to get me to orgasm and cum, I've never even been able to make myself cum. We have been together for the past year and a half and in the last few months I've stopped cumming and orgasming. I have a huge sex drive, we do all different sorts of different positions, speeds, clit-action(overly sensitive tho..), ect. The only cause I could think of is that his sex drive has decreased a lot and mine hasn't, making me feel insecure but last night he went crazy on me in the best way. It was perfect. I felt like I was on the edge of a cliff and i wanted to fall but i just couldn't. I couldn't cum. I couldn't get over that edge. He tried so hard, I don't know what to do. I'm frustrated. I Loved when I used to cum.. What do I do?