Sorry to hear that he's not getting any better :(

I agree with everything that Michael said. If you can't get him to a vet or speak to a vet about him then this link might be useful:

http://www.frogforum.net/tree-frogs/...tml#post124199

It's an old post I just found about the most humane ways to euthanise a frog. If it doesn't link you to it directly then look for post number 36.