Handjob, what is wrong with me?!

I've been dating my boyfriend for a year now (we're both 17), we have sex frequently, but I've neber gave him a blowjob and only did a handjob once. We were at our close friend's party and he was a little drunk and we went to sleep and he kind of asked me to do a handjob and I said okay. It all went smoothly, al least I thought so. The next day we were talking and I asked him how was it on a scale of 10. He said 6 and from that day I can't even lay my hands on that area. I don't know what happened, but it hurt me so nuch and I got so self-conscious that I can't do anything about it. It's been about 6months or so.. We have sex, but I can't even touch his penis or what so ever. All I think about is that I will fail and he won't like it and so on.. What can I do? I feel as I am letting bot of us down.