My Dog's Utter Fear of Stairs?

Speak first to your vet, he may be able to give you a tranquilizer so you can calm his fear long enough to get him using the stairs. Gradually reduce the amount till he can use them. It is an unreasonable fear and he shouldn't be forced, he can't help it. Failing that or if you don't want to drug him, an animal behaiourist may be able to help you. They use a combination of animal phsycology and dog whispering and you can learn a lot from them too.