have i got ocd or is it just another form of self harm ?

hi my names emma and im 15 , about a year ago i started scratching my hand untill i could see all the skin coming off but eventually it would bleed , then i stoped but then just befor christmas i started again, i started talking to teachers at school because i dont really talk tomy parents at home because of tuff going on , and they told me it was down to stress , then i started cuttingmyself  untill aboiut 2 weeks ago and ive ost a lot of weight , my head of year toldme tht was stress aswell, then recently ive started scratching/rubbing places like my lips eyebrows and scalp  untill i see little bits of white things coming off, but isit a form of self harming ? or someone told me it could be ocd ?? i really need to no what i should do and know that other people do it ?? also randomlyy my parents toldme that ive scratched ever since i was like 6 but i dont remeber it and i stopeed for like 6 years so what is it ?what do i do ???? thank you xxx