My old boy has Dry Eye and has Optimmune Ointment for it, which is cyclosporine and is usually the only way to stop the disease progressing. Perhaps your vet will prescribe it when you go tomorrow?
Optimmune doesn't sting, so if you end up with it that should help in more ways than one. I've found with William that a daily routine of the ointment followed by a treat works well for him. I get the Optimmune tube and a tasty treat out and when he sees them he hops onto the sofa, which is an easy place for me to apply the ointment, and sits. I apply the ointment and then he gets the treat and some praise. He doesn't enjoy the process but he endures it without fuss because he understands the routine and knows that it ends with something nice.
If you end up being prescribed Optimmune please post again and I'll give you a few tips about buying and using it.