Hair Loss, Weak Erections, And Growth Spurt At 21

Cliff Notes: I'm 21 and in good shape. Six months ago I noticed hair loss, weak erections, and decreased libido, all of which have continued. The hair loss is getting pretty bad. In the past 3-4 months I also grew half an inch. I haven't grown measurably since I was 16. I'm worried (not about the growth, but in my unprofessional opinion I can only assume its related).
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First some background info. I hit my major growth spurt at around twelve, I was 5'6" at 12, 6' at 13, 6'2" at 15, and 6'2.5" at 18. I've played basketball regularly since I was 15, and when I got to college I started lifting weights too. I'm in great shape, and I eat lots of fruits, milk, eggs, vegetables, nuts, etc. (although I am vegetarian).

When I hit puberty, I had pretty bad dandruff and hair loss. I didn't worry about either one since I had a thick head of hair, and by the time I finished high school both problems resolved themselves. Once in a while after that I would see some hair loss for a week or two, but I never worried about it until a few months ago.

Six months ago my hair started to fall, and it hasn't stopped since. For the first month or so I ignored it and assumed it would fix itself, but it hasn't. I've noticed not only that the hair is falling, but a lot of individual strands are becoming thinner. From what I understand, this is a sign of DHT and male pattern baldness. The hair loss seems to be evenly distributed over my scalp, but if I had to pinpoint the area with the most hair loss I guess it would be the crown of my head. I never paid attention to my hair loss in the past, so I don't know if this is the same as what happened back when I was a kid. Regardless, my hair is getting very thin and I'm going to start looking bald if I don't do something soon.

Also, at the same time (six months ago), my erections became weaker and less spontaneous, and I noticed a decrease in libido. I do and did masturbate a fair bit on and off since I was a kid, and I've read some articles about over masturbation, but I'm not sure if I buy into it completely. A lot of people seem skeptical and think its more of a scam than anything else. The hair loss combined with this make me a bit unsure. Either way, I've stopped all sexual activity completely until I get these problems sorted out.

The kicker here is that I also grew half an inch over the past 3-4 months. Everyone had been commenting that I looked taller, and after measuring myself I am definitely taller. That doesn't seem to be the sort of thing that would go along with over-masturbation, but then again I'm no expert.

So there are my two problems. I have no idea if the are related or not, but the hair loss and weak erections started at the same time so it would seem they are. I don't know where the growth fits in, if its related at all. I'd appreciate any and all help I could get, I'm really getting worried. I'm willing to do whatever it takes to get back to where I was, or as close as possible.