My family is too stressful and something must be done.?

My grades have fallen and i am starting to feel depressed and unhappy all the time. My extended family recognizes the problem that i am having. They are unaware of the severity, but they know i cannot stay with my parents any longer. I am wondering, do i have a choice in potentially being emancipated, or staying with a friend, or do i automatically have to go to part of my extended family. My grandparents have always taken care of me in the past, but i don't see that as the best option for me anymore, what rights do they, or my parents, or i have in this matter? I am almost 16 and live in PA.