I need advice!!! What to do?!?

I am going off to college in less then four months and everything is crumbling around me. My friendships and school life and home life. My best friend (of almost four years) and I just had a humongous fight, that might destroy our friendship. I feel like throughout everything I am doing I honestly don't have any idea what I should do. Does anyone have any advice for a Senior going into college? I really need some advice! I don't know why all the sudden everything is falling apart but it is and I don't know how to deal with it and/ or fix it. Please help!