Been there and done that I'm affraid.
At some point you will have to move on and leave him to his ways. Some friends are not lifelong.
You are doing the right thing. Do not lend him money unless you are comfortable with the fact that it is a gift.
The urge to accomplish must come from within and as long as he is being taken care of, that drive is non-existant. Too much pot in the wrong
circumstances will have that effect. I've been there too.