I’m sorry your feeling like this. I think your doing amazingly well. There is only so much a human can do for someone else… I’m sorry he wasn’t very dedicated yet to being med compliant. I’m hoping that this time in the shelter where others tell him what to do will help turn him around.
Also, negative symptoms creep up so slowly, and then 
. It’s the negative symptoms I fear more then the positive ones. But please don’t blame yourself for not knowing or seeing this because they really do come on quarter inch by quarter inch.
I think taking him out, keeping him plugged in to the Y and all that will prove to be a benefit in the long run. I’m wishing the best for you.