My brother is POA and refuses to let my disabled Mom enter a NH. What can I do?

She is becoming mentally incompetent, legally blind, diabetic, and incontinent. We all three live in his home. He works and I care for my mother full time and him. He doesn't drive at all. I mow, take care of all appts., medication...etc. The house is falling to pieces. Mold, ceiling falling in, cabinets falling off the walls, roof leaking. Mom needs a new mattress, grab bars for the shower, somewhere to sit other than a kitchen chair and he refuses to allow me to get any of this for her. He works, sleeps, and goes to the VFW nightly. Even with both of us there, the caregiving is becoming overwhelming. Neither one of us gets over three hours sleep a night because mom stays up at night and takes naps during the day. She has quite a bit of money of which my brother is in charge. He uses her money to pay his electric bill, taxes, cable, newspaper subscriptions...everything! I know she now needs more care than we can give her and would like to find her a nice NH in which to live. He adamantly refuses because of the money. I am 53 and have no job, insurance, 401K...nothing. I feel used by my brother. I never signed on to be HIS caretaker. I want my mom to get the very best care possible which I can no longer give her. I think her money should be used for her. He is doing his utmost to hang onto every penny. He has started yelling at her a lot lately, too. I told the Home Health nurse who comes in to give her a bath and she seemed completely unconcerned. What can I do? Is this abuse??