My bf and i keep breaking up and getting back together only to break up over the same things..what should i do?

okay so i have been on and off with my boyfriend for about 3 years. the past year or so has been really tough. it seems like we fight all the time over stupid little things. i guess i should just start from the beginning. first off hes a gemini and im a picses, if that helps. it wasnt til about december of 08 that we actually started getting serious, you know taking about moving in together, having kids, getting married....that sort of thing. i have a lot of guy friends and he has a lot of girl friends. it started on new years 08 i had gotten dropped off by one of my guy friends at my bf friends house(where he was, he invited me to the new years party) well he got mad that another guy dropped me off, understandable. but then he goes and calls up his ex so i figured hes not into me so i made out with a guy at the party, he got really mad and we;ve been fighting about it ever since, literally he brings it up all the time. then from there i think he let the new years party incident go, and we started talking again. well every other week he would have a new excuse to break up with me...rather it be he just wants to be friends to hes got commitment issuses. this goes on and on til about june 09 and i can never tell if hes serious with me. one day hes like i want to marry you then the next day he says he hates me and wants me out of his life. we break up for about 2 months in june( usually we break up and argue til we come to a equal and "work things out " and just get back together) this time we actually broke up for 2 months without talking. then he said he was just being an *** trying to make me learn. when he and i break up he always goes back to his little girl friends so i figure ill do the same and move on, but then apparently im at a wrong by doing that. a guy friend of mine had messaged me over myspace and i replied and deleted the message cuz i knew my bf would get mad. ( the message wasnt bad, i wasnt flirting, the guy wasnt flirting with me) he just doesnt like me talking to ANY guys. not even ones ive been just friends with since before i met him. okay so we keep breaking up cuz he says im keeping these guys around which i do not beleive is true. im just a really nice person and i knew this guy liked me and i didnt want to hurt his feelings so i tried to come up with many different ways to get him out of my life without actually being a ***** about it. so i told him i got my phone turned off. i deleted him from my myspace. and eventually i straight up told him to quit talking to me.( this is all the guy friend, not my bf) well my bf finds the message in my myspace trash and gets mad and breaks up with me. i guess i kind of understand where he is coming from. point is we fight a lot over things that have happened in the past, things i thought he got over and let go of. i feel like any time we are doing better he just goes and brings up things from my past so we'll fight. what does that mean? just last night he wont me up in the middle of the night and asked who someone was on my comments on myspace, someone i use to talk to and i was just gonna say hey see how they were ( because he was talking to his little girl friends again) he flipped out and broke up with me again. i dont know if its all the stress thats causing us to fight or what. his dad just got diagnosed with cancer about 8 months ago and they thought he was getting better but it spread and now they only gave him 8 months to live. my bf is also having a hard time getting into the air force because of some trouble hes gotten into in his past. he cant find a job and his gma just died. i just want to know what should i do about this whole situation? should i keep fighting for our relationship or let him go and move on. i love this boy to death and i want nothing more than to be with him til the day i die but i cant stand him bringing up my past every other day, and ive told him how much it bothers me. ive quit talking to all my friends and he says i cant talk to any guys but he can talk to any girl he wants! i just am clueless as to whats going through his mind....WHAT SHOULD I DO?