dumbbells worked for me for a bit as did a few yoga type stretches, but ultimately my biggest solution was actually posture sitting at my desk at work. Recently moved office I had a curved desk before which ment I was always slouched to one side, Last few months before I moved were terrible, I think my sitting position was just compounding the problem. Now at a straight desk with a chair that pretty much forces me to sit up straight on. My trapped nerve issue went away overnight. I think some weight loss and getting bit fitter also helped mind.
For pure pain relief, pain killers are useless.
Weed is very good for it btw, talking pure pain relief. (not advocating drug use, just state some personal experience.) But that’s just a mask and not a solution, it’s also very good for cubital tunnel syndrome, but again, just a mask, finding the right exercises is a better solution for that and getting to the source of the problem is better.
I think the ultimate problem is that it is actually just a trapped nerve, you need to find the nerve and exercise it, that’s the difficult bit, no usually where the pain is.