Hello, I am a 24 year old male with a problem that I fear is ruining my relationship with my girlfriend. I am a virgin but she is not. Over the past week we have tried to have sex three times but for some reason I cannot get to the point where I cum. I have looked around on here and have seen some posts regarding masturbation and needing to wait a little while for the sensitivity to return, but I don't know if it is this or not. I can cum when I masturbate, but not with her. I don't know if it is just me being nervous but every time it happens it just makes me that much more nervous the next time. Should I go to a doctor? My girlfriend is starting to blame herself. She asked me last night if I didn't think she was sexy enough or if I was thinking of someone else during sex. I tried to reassure her that it has nothing to do with her and that I just don't know what is going on because it's now, but I don't really think she believed me. She is the most wonderful person I have ever met and would hate for this to come between us. If anyone could help me out with this I would greatly appreciate it.