Hello; I am 19 years old and I have no history of physical illnesses personally (in my family there is some arthritis, diabetes, and literally half my blood relatives have or have had some kind of psychological problem). When I am alone and masturbating, I generally have no problems maintaining an erection, unless for some reason I'm unable to concentrate on my fantasies; and I certainly don't have a problem with my sex drive itself, i.e. my desire for sex. When with a girl, I also have no trouble maintaining an erection during mutual masturbation or oral sex. However, when it comes to actual penetration, my erection almost invariably disappears before we can even start. I have only successfully had sex twice, with my first partner; my second partner was only ever able to please me through oral sex (keep in mind, though, my relationships have been exceptionally short - a few months in the case of the first, one month in the case of the second). As you can imagine, this is extremely stressful and emotionally painful, and puts me off making advances on other women for fear of the same problems cropping up again and again. I am on the cusp of a third relationship, now, and I am worried that the same problem will appear again. I don't doubt it's a psychological problem - I have had my fair share of mental troubles (bipolar phases in early high school, hysteria, hypochondria, general anxiety disorder, almost all the symptoms of four personality disorders, most of the inattention-focused ADHD symptoms), and as I've said, there are otherwise no problems at all with my erections - but all this advice of "just relax" or "don't think about it" or "focus on your partner" does nothing for me. Even when I do appear to have cleared my mind, it still fails, and I am inevitably reminded of all my previous failures, and at that point it's just too late. I was prescribed a packet of Cialis by a doctor I visited, which I have not yet had the chance to use since my second relationship broke up. I don't want to spend the rest of my life relying on a little pill to satisfy my sexual needs, however. Is there anything more specific and systematic than "relax, don't think about it" that I can do to solve this problem? Something that actually helps? What could the problem be? How can I fix it? Any help would be enormously appreciated!