This sounds like the START of carpal tunnel.

First, I would do a search here at Mudcat on CARPAL TUNNEL. Search also on PAIN. Then, read the recent thread on autoharps and some of the older ones. You can click on my name in this post's header and look within the list that will come up, for autoharp threads. (If the list takes too long to load, or locks your computer, just let the list load partway and then hit the STOP button on your browser and you will get a partial list.)

In brief, I play mine tabletop, tilted toward me slightly, and upside down. And amplified so I don't have to strum so hard to get a nice clear tone.

I'd search up those threads for you if I weren't having the compueter and modem problems I'm having-- but good luck!