Thanks RMCAD, PHL, BDlvr for all the great info.
I've gotten rid of the red bulb.
I took him to a vet who recommended an additional ceramic heat bulb. Now the ambient temp is 80 and there is a basking spot of 105. (Before the ambient was about 70-75 and the basking spot was 95.) But there has been no change. He hasn't eaten a thing and now is barely moving at all.
He has always been offered greens, only eating them occasionally. But now it really doesn't matter what I offer him because he hasn't eaten now in 11 or 12 days.
I don't know what the hell to do. I will take him back to the vet I guess. And if it turns out that despite my efforts I am just too much of an idiot to keep a bearded dragon alive I guess I will look for someone more qualified to rescue him.
By the way, the vet was listed on a link I got from this board for reptile vets... but he is a vet for all kinds of animals (dogs, cats) in addition to reptiles. Is that ok? Or should I look for someone else?

