Yeah I’ve experienced this. It’s quite irritating that when you care for a girl it’s harder to perform, at least sometimes (hello Oeidopus!?). To be honest, the best sex I’ve ever had was with a girl who’s opinion didn’t matter to me at all. I couldn’t care less if she thought I was good/bad in bed, if she didn’t like my penis or whatever and I guess that made me relax and I was able to really enjoy it. It’s not a very healthy attitude towards sex and I hope I’ll get over it in time.