Cat just wetting my bed?

We go him groomed and we thought he was going to be put out, but wasn't he was shaking when we picked him up I was furious, and he wet in my bed that night, ok got the Miracle liquid washed everything bought new quilt and bedsheets, well the next night he did it again. Our vet told us it's behavioral, plus when I got him home he started rubbing his rear-end and licking himself took him to the vet hospital told me he was shaved to close and along his tail, I was told this wetting problem s going to be hard to break or if it can be broken at all. I am heartbroken that I may have to find him a new home on top of all the medical problems he had when we got him and I won't go into it, but 3,000 dollars later he is well and now he is wetting the bed and it's not a urinary problem, I have been so upset about this situation I called the humane Society where I got him and they told me that they would probably be put to sleep and that they couldn't place him he is only 9 months old, he was 7 months when we got him and I can't have him put to sleep, I don't know what to do??