What am i supposed to do?

every night for the past couple months now ive been sneaking out to meet my friends and my boyfriend. just last night out one friends came over and was spending the night at my bf's house. the guy says that he likes me but he's a 'demon' an d that 'should stay away or i might get hurt". blah,blah. last night he got off of the phone but he was insanely mad. both of the guys think they are ninjas and act like they can take any kind of pain let it be mental of physical. so the friend asked if he could punch my bf and he said sure. im assuming that it wasn't enough so we went to this church and he punched the mailbox. at first it was just a dent but he punched it a second time and it broke. of .completely. now the mailbox was already insanely old because i remember that one time i opened it because they was a spider stuck inside and they whole thing nearly broke off. we fixed but i didn't touch it after that. anyway, so at first i thought it was SO hilarious and we walked back to my bf's house and i laughed the whole way. too funny,especially with tomorrow (today) being sunday. but then the people that live across the way from the church drove up and asked the friend if he had seen the kids who broke the mailbox. he told him WAY down the street. automatically i freaked. when the friend finally calmed down from what had pissed him off earlier, he decided he was going inside. i was so upset! how could he act so casual after we had almost gotten caught? he said good night to me but in return i punched him in the face and repeatedly slapped him like "what the hell is wrong with you?" he just stood his ground , and went inside after banging his fist on a mailbox. my bf is just sitting there like "what the hell" even though he says nothing. im guessing he's thinking that i suck for being so freaked. im standing here almost ripping the hair from my head instantly regretting hitting the friend and still stressing about getting caught. just a little while ago i broke up with my bf through a message on facebook.. idk if he's seen it yet but im thinking its just the right thing to do at this point. we've been dating on and off, i know that he's the reason for all these headaches,the reason that i constantly feel depressed. he's the reason why i had to worry for two weeks about whether i was pregnant or not ,even though im thirteen and he's two years older. ( im not pregnant) its just too much yet he's like a drug that i know i should quit but im keep buying. he's irresistable and no matter how angry i can get at him , i still love him. and yeah it sounds cliche . a thirteen year old girl thinking that she knows what Love is and that sh'e madly in it but its true. if i didnt love him my feeling would have left months ago. we've been doing the o-yo dating thing for like a year or two now). without him, i feel numb. like im incomplete. like he is the only thing and person that can and has been keeping me sane night after night. i know i love hm, but its just too much. what do i do/ help me please, because im confused. i just cant do this anymore.