Until you're absolutely sure, don't begin anything of change like that. In fact, before any decent doctor will give you such hormonal treatment, you have to have some evals anyway, I think.

Being unsure of oneself at that age is normal. You mention low self esteem and depression. You might also post in the depression forum. There you will find how depression lies to you, telling you things that just aren't so, making you feel worse for the thoughts too!

Maybe "change" is what you want, as most people with depression say they want. But when they say it, if often comes out as not wanting to live. Maybe your depression is saying you just don't want to live the way you are anymore, and you're thinking if you change what you look like and how you act to fit (or vice versa) then you won't be confused and won't be depressed? If that's the cause, making such a huge change won't help either.

Do you have someone to talk these issues over with, like a counselor? If not, you might consider having a free consultation with a psychologist about how therapy can help you feel better about who you, and who you want to be.

TC.