recently i received a small amount of adderall from a coworker.

over the past few days i have tried it at work and at home,
and honestly, i feel functional. like i imagine other people feel all the time.
usually my thoughts are pretty muddled, it was refreshing to feel clear headed.

my question is;
where do i go to see if its something i can get a prescription for?

i am 20, caucasian and male.
when i was ten or so a school counselor or social worker or something said i might have ADHD, but i was never formally diagnosed.