OP:
I just thought of something. Maybe a static discharge mat like these would work for you?
They offer a high impedance path to ground, so it may take a few seconds to dissipate a static charge you build up. Not honestly sure how well they’d work in your situation, but certainly would prevent the pain.
Another alternative is a metal key. The large surface area of the key means you don’t discharge from 1 point, making it less painful.