My friend is turning every one against me?

a few days ago me and a friend were in cl. im very very patriotic and he started trash talking some stuff that got me mad, so i said dude shut up. he then flew off the handle calling me a p*ssy and a b**ch and a bunch of other stuff, i didn't feel like dealing with it and starting any more stuff so i let it go and didn't say anything. instead of coming to me like a man and tell me to my face he texted me a bunch of really really rude things and used some personal stuff to really hurt me. i ignored his texts cause i didn't want any trouble and i really don't care about all this high school drama crap. he then calls and texts everyone he knows telling how bad i am and how much of an a** i am. i found out about this and still chose to turn the other cheek cause i just don't care that much. i care now cause i have a friend who's leaving for the army in a month and we are all having a BBQ for him as a going away party, and this person convinced him to tell me not to bother coming. i was needless to say, upset cause me and my friend going in the army are good friends. i really really want to say enough is enough and go confront the first person but if it turns ugly this is the last two weeks of school and if i get suspended i can take my finals and i fail. any advice?