I had a similar problem last year. My fingers hurt, then went all tingly/numb. I took a few weeks off and now shoot a little less. I try not to do any marathon shooting sessions. I have so much fun shooting that I lose track of time and end up shooting for an hour or more; It's fun but too much of a good thing.
Once my fingers felt more or less normal, I added a layer of leather to the inside of my tab. Also, I was leaning forward into the target, causing more pressure on my ring-finger; straightening my stance helped quite a bit. Good form (mine is only about half good) can make a big difference.