Friend vs guy...?

so i have this bestfriend who is datin this guy that i hate...he treats me like crap && he always messages me on myspace talkin crap...he thinks hes all that && everythin is bout him....my boyfriend read the messages && got pissed...so of course as protective as he is my boy jumped the kid with a bunch of his friends....my bestfriend got mad at me && told me that it was my idea && my fault...but the truth is i didnt kno the kid got jumped until after it happend...she told me she wasnt goin to talk to me...i dont kno what to do...i'm sick of the crap...i hate her man && i hate the way she treats me when hes around or on the phone...what should i do??