Norm:
My heart breaks for you in such a terrible situation. Since you live in an apartment, I guess a buddy for your dog is probably out of the question? I know it would be rough, but it sounds like the only humane thing to do would be to try and find the dog a good home where he can have a friend or human close by all the time. I have a hard time with bark collars, and TOTALLY disagree with de-barking.