Rebar to cull them.
Unless they break a leg by accident or bite each other, everything else gets culled.
Wool block gets cooking oil, if that doesn't help, cull.
Ear mites, cooking oil, again, if that doesn't work, cull.
Mine never got wormed, even on the ground, no worms. But Cocci, that is a real issue and I bred for resistance. Otherwise, you guessed it, culled!
Too many people get lenient with rabbits, unlike other livestock. That just equals crappy animals for others that you sell to. Cull hard and carefully.
Breed the best, eat the rest!!
I never used anything for pain management, because if a rabbit is in so much pain to actually show it to you, that means it's on death's door. Prey animals only show pain when it's truly about to do them in. Otherwise, they hide it and hide it well.
I don't know of any safe drugs for pain management for rabbits.