You are barely losing your hair, at least in your pics unless your using some type of concealer.
If you want to shave your head--great. But you dont HAVE to. 

Exactly.  Your hair looks fine so if aren't ready to shave it all off, then don't.  And you definitely don't need the drugs or HT either.

To answer your other question, a #3 buzz would look fine.  In fact, #3 is not even that short, so go for it.  If and when your hair loss worsens, then take it down a little shorter.   A lot of times, it's easier to make the transition gradually.

I used to have the same concerns about going sly. Once I did it, though, I liked it immediately. It's been only 24 days for me but I've already been told many times that I have a nicely shaped head.

To the OP: you don't look like you're balding. You might have a slight receding hair line, but it's not a big deal. When I was in your shoes (I was 20/21, started to have a receding hairline at 17), I started shaving it shorter and shorter. First with a 3, 2, 1, so on. At 21 the thinning was really bad, so I started using a 0 guard. I've been using a 0 guard for while, but have just now started using a razor. Try that...you will still have hair for a while.

OR

Be really brave, shave it off, and see how you like it. I bet you'll look good. It will grow back if you want grow it out again. I think your hang ups on your physical appearance go deeper than your looks. You're no Tom Brady (who is?), but you're not a bad looking dude.

Trust me...the relief of not having to worry about your hair after you shave it is priceless.