I hate myself, its lke im at a breaking point, but ive got what i want? HELP.?

im sixteen and just left school (in the uk, we leave school at 16, then have summer break then go to college) . ive always been a quiet, reserved girl, who never really got boys attention. i liked this guy for 4 years, we met up one year and kissed n stuff and he said he liked me but didnt wanaa go out with me. lately ive been getting over him, meeting up with my friend and her boyfriend and his friend, his friend seems interested but hes on holiday at the moment, the other night me and my friend went out with my cousin, whos a guy and the guy i liked for four years was there, he kissed me and i kissed back (i was a little tipsy) and he asked me out, saying i was dumb for being a ******** to you. but now ive moved on! i dont no what to do! and then his bestfriend is texting me 24/7 saying he likes me aswell! and that will i give him a try. from all of this im also going through a stage of what i think is self confidence, and depression problems. i hate myself, since 13 i have, i get emotional to the point where one second im bouncing off the walls, to the next im attempting to self halm, over nothing. aswell as this my bestfriend is being a little ***** because shes so stubborn! and she knows how to make me feel like crap. i trust her, and tell her how i feel, and she uses it against me when shes mad at me. i feel like i need to speak to a doctor.. and before trying to find someone to respect me and have a relationship with, i need to learn how to respect myself and my own body? do you think that?