Is it legal for my brother to keep me away from my mother who is dying of Alzhimier's (90)?

He is very violent im scared. He has kept our whole family away including my Mother's two Brother's, friends, church members and nieces and nephews. I call and beg him to let me just tell her i love her and he is now going to file a restraining order on me, can he do that? He also said he was keeping my trust from me as well and it has been two years now and i dont know what to do anymore. I took care of her before the stroke for years at my home because he was abusive towards her and myself. What do i do? Would a judge listen to him and how can i be there to fight this ridiculous restraining order? He has no power of attorney my mom refuses to sign it! She wants to see me everything was wonderful until he did this!