Please hlp me!!! I have a serious problem and dont know what to do?

I moved from California to new york with my grandma because i had many family problems. I left three brothers, a sister, and my parents behind. Also friends that might as well been family. I loved them so much. Now my brother and father are facing many years in prison. My sister is left alone because she cannot move in with my mother and my other two brothers. She is a little suicidal and loves her family very much. Should i leave my new home to support my sister or should i stay in new york. I really dont know what to do