Dominick, I think you should do some reading on finasteride--Wikipedia is a good place to start, but don't stop there. There is evidence of certain long-term effects (I wasn't too worried about some of them because I don't have typical sexual equipment) and evidence that one side effect is depression or anxiety. If you have a lot of depression or anxiety issues, then this med might not be for you.
I have depression, but I've been doing better with my depression, not worse, in the two years since I started this med. There have been bumps on the road, but (as far as I can tell), they've all come from life events and my own developmental arc, not the med.
If you are losing hair on the top of your head--the crown rather than just the hairline--then topical Rogaine could be a possibility. You don't need a prescription. Rogaine is apparently bad for cats and some other animals, so you have to be careful about that. My old cat liked to strop my head, so I never seriously considered Rogaine--and anyway, I don't seem to have hair loss at the crown, only at the hairline.
I well understand your anxiety about hair loss, especially given how young you are. Most cis men are concerned about hair loss, so why should a trans man be any different? I hear a lot of trans guys saying that if you're not prepared to lose your hair, then T isn't for you. Some say that they don't mind the hair loss because it's what most men face at some point in their lives. Those attitudes clearly work for other guys, but nobody can tell you how YOU should approach transition. However, I feel that you ought to educate yourself enough to be able to converse intelligently with your doctor(s) about your options--so if your docs aren't being straight with you, you will know it and be able to ask more questions or call them on it or decide to go elsewhere, or whatever. To a certain extent, knowledge is indeed power.
P.S. The clinic where my friend went was some kind of unorthodox women's clinic...I don't know how he found it, but Smitty seems to have provided URLs and tips for you.