The only thing I can think of is to keep this guy in a separate area and maybe give him some medication, prescribed by the doctor.

I just know that other folks will have good ideas for you. It seems such a shame to put him down. There must be some little old lady looking for a cat to keep her company. Try to find him a new home! Is that possible?

Help needed here, everyone!

Good luck. Don't get rid of this poor guy. He sounds like a wonderful cat.