This could well come down to waiting until he is out at work and then changing the locks so he can't get back in. That is what an elderly lady I know had to do, her son was on drugs , so the situation was similar. The police were very helpful and attended when he came back and tried to get in.
They took him into the house to collect his clothes and then made sure he left the area.
He will get benefits, I know a man who was a registered alcoholic , that is classed as an illness , and he got benefit money as a disabled person would.
I also say the CAB are your best bet in the first instance .