u/CompetitiveRange6673

So, to start I am still at a young age (20). Recently I started having a problem during sex. I start with my girl my penis erect normally, I feel the urge to taste her, touch her, play with her and I give her and gives me oral which goes very well. The problem starts when we start sex. I start, going for some seconds or minutes and then I lose my erection. This has started some weeks ago with a failure again at erection during sex, but after this I had decent sex without any problems, but this incident stayed in my back of my mind and two days now, yesterday and today, happened again and made my psychological condition a lot worse. I am thinking about doing some testosterone examinations at a doctor, but I don't think it's the main reason. Also, because of this the time I get erections during the day are less than before, I need an opinion on this, because I am not feeling very well now. I still like women and I like to play with them, but this... Ahh it's tough for me. Please help!