Erectile Dysfunction :: Never Been Able To Hold An Erection

30 years old, somewhat overweight but not in terrible shape, occasional drinker but not more than that, busy lifestyle (work a desk job and moderate exercise). No other biological issues other than that I suspect my father had/has been treated for low testosterone at some point. I sometimes feel like my sex drive mentally isn't what it should be as compared to other men, but I do think about it albeit with some apprehension at this point. I don't struggle with feeling attraction to women at all. I take a daily vitamin so I should be fairly well covered there.

My problems? My erections come slower than molasses and when they do come, I struggle to maintain them and they usually fade away within a couple of minutes, even while actively engaged in sexual relations. It is not for lack of confidence as I have been told that I am quite good in my bits and spurts, but I have never gotten off during sex despite desperately wanting to. I am capable of getting very hard but it rarely lasts long enough to have any kind of meaningful sex.

I also struggle with masturbation. I can make myself get hard by thinking about it, playing with myself, but the same problems occur - I can't get myself completely lost in it and my erection goes from very strong to non-existent in the span of a couple of minutes. There is one exception, however (and this isn't much fun to admit, but I figure it's the only way I can get help for my condition) - if I lie on the floor and rub myself against it as a form of masturbation, I can get quite hard and ejaculate just fine within a couple of minutes.

I'd like to have a normal and active sex life, because this has destroyed or at least undermined every relationship I have ever been in since I was a teenager (this has gone on since I was 1. I don't think there is anything drastically wrong with me physically since I still feel a semblance of sex drive and can ejaculate, but the blood flow and maybe the "immersion" in the moment just doesn't seem to be there.

I (FINALLY!) have an appointment with an urologist coming up in a couple of weeks, but I am in a relationship where I am mentally and physically ready to have sex, and I am dreading the same old of trying to take it to the next level and failing spectacularly. Does anybody have any idea of what might be afflicting me? Is this ED or is it possibly something else? I'm thinking about trying something like yohimbe (very small dose) or gingko as a short-term remedy, will these help me at all?