I am a healthy 23 year old guy. Me and my girlfriend had sex twice within a few hours but not continuous (after a few hours) and then later when we had sex for the third time I tend to lose my erection after 10 mins of having sex. I workout daily and I don't have any physical problem. I don't have any problem masturbating. I am worried that my condition is due to performance anxiety.Is it normal to lose erection like that?