I am not experiencing the same thing, but have had an ongoing pronblem in my neck and back that cause me constant pain, day in and day out, of varying degrees. And the nerve gets pinched so I get numbness in my left leg when riding. It's not screaming agony pain, but just a kind of incessant pain that wears a person down. I went riding yesterday and it made the whole pain flair up again. So, all this is to say, I know how scary it can feel if you start to thinking that "I'll have to give up riding". I might look into a gel seat myself. I have sheepskin on, but it's pretty worn out.
I hope you find relief soon, and of a permanent nature.