STOP feeding him mealworms imediately! Their exoskeleton is comprised of too much chitin that is undigestable and can cause an impaction. This is more than likely why he had a prolapse. From now on you should feed him earthworms or night crawlers. They are very easy to digest and do not cause impaction. They actually make it easier for them to poop. Crickets are also fine. Try waxworms as well absolutely no more mealworms or superworms.
I'm sorry, but I cannot say for sure whether he will die or not. If his bowels continue to be unable to work properly then the outcome looks grim. I wish theire was more I could do from here, but I'm extremely limited from across the world.
Post some pictures of him and his home. Try the advise that I've given and see if it helps him.
Keep me. Posted.