My sister is behaving absurdly. Over it?

I observed during my mother's illness that my siblings were insensitive people, they were more bothered about the money than her recovery. I pleaded my siblings to care but it was of no avail. When my mom passed away, I felt quite alone. Yet I managed it by being busy in creative works. But then my sister fell ill and needed me. I supported her as I am still attached to both of my siblings.  She had afterwards a fight with my brother for being greedy and insensitive. I still supported her in that fight. I became the villain for my brother and his family in doing that. Now my sister has cornered me and she has manipulated the whole family against me by insinuating that I provoked her to fight. She calls me names and doesn't talk to me. I try to shift my focus to creative things but I am falling into depression. How can I get over it?