helping my brother with short term memory loss as his guardian

I am at a loss. My brother lost his wife and continued to drink heavily. Became real sick and ended up with dementia/short term memory loss. He was able to gain a little back but I don't know what to do. I took him away from his home because there was no one there to care for him when he left the hospital. My husband I were hoping he would recover so he could go home. After a year with us, right now he's in a locked dementia unit and is only 60. To speak to him at first he is a normal person until after a while you can realize. He cannot remember how many times he speaks to us or when we visit. There's so much more going on but it's so hard to explain. The step son is there at the house and he would take advantage of my brother. he's unreliable and sneaky but all my brother wants is to go home. Which we all can understand. He feels like a poisoner and although he's being well cared for, it is not the appropriate place for him. He is on Medicaid and there aren't a lot of options. He escaped one but they brought him back. He really needs more freedom in an assisted living but would just take off and try to hitch hike home.