Different country but still, I know you can get everything over the counter in Romania. Maybe in Bulgaria too? I won't give you a list of things here though.
But ya it's better to go the official way if there is such a thing in Bulgaria. It's best to get in touch with LGBT communities and ask around there.
It can also help to call your insurance and ask around there. At least here in the NL they'll make sure you get in contact with the right person. Because trust me there are lots of psychologists etc who have no clue what they're doing with Trans issues and you'll burn your fingers real bad.