im 18 and i have a problem. me and my girlfriend live about 4 hours away and i go see her every 2 weeks. usually when im there, we have sex anywhere from 1 time to 8 times or even more in one weekend. however this last visit didnt go so well. the first night i was there i was fine but while wearing a condom i find it a lil bit difficult to keep a strong erection. this has only been happening lately. every now and then me and her use the pull out method (shes on birth control) because not wearing one just feels better to us. I can keep a strong erection with no problem if i dont wear one. this weekend however, i could only go one session of sex and could not get another erection for quite some time or not at all. usually i get hard if the wind blows. usually when we're done once i dont even get soft it just stays hard. this is shocking me and im all stressed out about it. the only thing i can think of is that when we use the pull out method, i have to jack myself off with my own hand to finish cumming, and it aint all that great. when she makes me cum with her hands or hands + mouth it feels a million times better and maybe that is making the difference. please help