To keep it simple, first step is a bigger grip and I prefer the Tackimac Unified wrap, zero taper, allows you to swing with much less grip pressure in the bottom hand especially.
Second is go to graphite, although I won’t even swing steel anymore, so maybe in truth that’s step 1. I swing my 5 iron on your driver speed range, so I know for sure you can get something that works. I’d head to DTG and look at the Kujoh 95, it’s lighter, but not so bad that it hurts or golfstealsanddeals.com check out the program 130 gram shafts, steel weight, tour performance, dirt cheap.
I’m going to stay away from the medical side as I don’t know enough of the actual consequences of any of the options to give informed advice. I use ibuprofen, though my doc swears against it.
Also consider trying the overlap grip, it loses the finger twisting pain of the interlock, but more control than 10 finger, it has been a solid compromise for me.