Suggest Treatment For Prolonged Periods

So for over two years ive had this but idk whats wrong doctors say i may have hormone disorder... my period last for more then usual at time once they lasted for about 6 months i was 16 n now im about to turn 19 n my period has lasted over 3 months i dont want to go to the doctor they give me birth control n all that does is make me sick and get me really weak