I just posted this in the other thread you posted in, but it's better to post it here...
I don't know what the problem, so I'd just suggest going to doctors and specialists which it seems like you are doing. Hopefully one of the tests would reveal a problem.
As for your other problems, maybe I could allay some worry.
Facial hair is a very odd thing it seems. Out of my three main friends and myself, not one of us has the ability to get a full beard and/or mustache. My hair grows thick and fast along the jawline and below, but the front of my face has very few and sparse hairs. Perhaps a couple hundred spread out in random spots. I can't even grow full sideburns. Other friends have spots that won't grow hair at all really. Body hair is even more random as many men will never have much.
Only two wet dreams? I don't think I've ever had even one, and I'm 27. That's likely because I've masturbated regularly since I was 11 or 12. So I've probably never gone long enough for my body to create the need for nocturnal emission.
Penis size is something hard to judge in the flaccid state. It's size will change easily and dramatically depending temperature, pressure, activity or what you have in your body, such as alcohol or drugs. Mine probably ranges from 3-4 inches normally, larger at times and unbelievably small at others. Since you've never had a full erection it's possible you could be average, but wouldn't know.
After you masturbate losing your sex drive is completely normal. It's a refractory period that nearly every male gets. I could masturbate and have the most beautiful naked woman walk in afterwards and ask me if I would like to have sex and I could say, "Nah, I'm good." Of course, I'd kick myself later. The refractory period is different for different people. It may be a few minutes or a couple hours. It can also be shorter than you think, but usually you're sated and do not seek arousal further.
Do you exercise at all? Eat fresh, raw fruits and vegetables? Not saying that's your problem, but you mention being healthy.
Are you aware of your pelvic floor muscles? Often called the PC muscles, more appropriately BC for males. These are the muscles you'd use to stop the flow of urine or defecation in the case of the rear muscles. Exercising these muscles can help make erections more rigid and upright for males, as well as making orgasms stronger. You can search the web for programs on PC exercises of Kegels.
Have you ever contracted these muscles regularly? Do you use them to reach orgasm?
Also, forgot to mention what Llewellyn already has. You shouldn't let this keep you from starting a relationship with a woman. There's more to life and relationships than just sex. Plus, sex is not just about penetration. It's about kissing, touching, oral, hands, closeness, bonding, etc. as well.