I have been taking tramadol, maximum dose, for 20 years and cannot walk without it. I am used to it, but need anti-nausea drugs as it causes sickness. Also causes insomnia. Good luck with Arch!
I cannot help with advice,but i am sending hugs to you and your dog,its awful when you feel like you cannot help them, i hope your vet can offer you something to do the trick without further suffering xx