Family Issues?

ummm ok I need some help. Im a 15 yr old girl who is going through alot. Me and my mom bicker constantly at stupid things. She says im lazy well yea kinda but im depressed all the time and she took me to the doctor and i got put on pills but didnt work so i stopped using them this happen twice. well now she dont do nothing about it. She complains to me saying wheres your pion for horses. well idk im never in the mood anymore i try to but then i get mad at the horse for not doin what i say. I have had friend issues over the last year and grandparent .vs. parents issues. I feel like i dont want to do anything but sit around. but see i think its because i havent had my mentrusal cycle in almost a yr. and its really irregualar. i talk to my mom about it and she says she will do something but never does. my grades are horrible too.Me and my dad get along fine. me and my brother well fight alot. plz help on what to do.I dont wanna feel like crap anymore. Thanks Kim