Very long relationship question..please help?

ok so im really lost and need some serious help from someone who doesn't know the guys involved...i already posted a question like a week asking for advice and once again im back in the same if not worse position of who to be with..im not sure if there is a way to see my previous question or not but im sorry if this one turns out to be long...so here goes, i ahve been with this guy for about a year and 3 months and we recently ahve been constantly breaking up over bs reasons...he cant seem to not talk to other girls and forst it was just over myspace and pissed me off but i always let it go and got back with him, then things went to new level this past weekend when for the second time in two weeks we broke up and he almost had with another girl whom i really dont like...i dont see how he could be ready to do that with someone else when we were together for so long and on top of that on our one year anniversery he actually proposed to me which i thought was kind of early but i love him to death becasue despite the bad there is some good to him....then there is the role of my besy guy friend coming into the picture. we have been friends for roughly 5 years also he took my virginity and although we never dated i have always loved him and we never fight and he is always there for me even when i out his own relationships in danger he always picks me over the girl...i waited on this boy for over a year and staid single to be with him but then as always he began dating someone else then about my 6 month of being with my boyfriend he told me he had always wanted to be with me and blah blah blah ...i have waited to hear this forever and love him so much but dont want to throw my relationship away but im sick of geting hurt and being taken for granted by my current boyfriend and i know my friend would never hurt me and after forgiving my boyfriend again last week we are already fighting again and he is up to the same **** expecting me to stay in all night so he knows what im doing while he is out doing god knows what...i dont know what to do im in love with two people and theres still so much to the story and i feel like an idiot for puting myself in this posistion and i dont know how to fix it, im scard im going to amke the wrong choice beacause i dont want to ruin a great friendship if things dont work out and i dont want to lose someone i love so much...please help...srry so long