It is always hard to let go, but I think this:

Originally Posted by
westtexas
Rehome him with the breed rescue he came from (they brought him to me to treat and I ended up taking him in)?
Also provide the organization with all that you have learned about him and what he will need in a new placement.
Trying to 'make it work' sounds like it will make for human, canine, and feline misery, unless you can miraculously locate a farm in the middle of the big city or something like that.
Each day is a gift, that's why it is called the present.