Too sensitive...?

Hi. I'm 16 and I guess i'm having a kind of "crisis". When I masterbate and especially if I go on my clit, after a little bit everything will me so intense with feeling that it almost hurts and overwhelms me and I have to stop immediately. I don't masterbate often because of this and because I don't get much from it. I'm afraid to ask anyone about this because I think something is wrong or maybe I just don't know what i'm doing. My boyfriend is becoming slightly suspicious and i'm not really sure what to do from here. If anyone would consider helping that would be great. Thanks!