Play with your fingertips, by that I mean literally the very tips of your fingers.
I used to hit the strings with the pads of my fingers, and, probably because I was also digging in a bit hard, used to get fatigued after about half an hour of fast playing.
I changed my style to almost brushing the strings, rather than plucking them and now I reckon I'd be be good for a four hour bar gig in Milwaukee.
You may experience a loss of volume, but let the amp take the strain.