I developed a weakness in my wrists a couple of years ago where I found my STI brifters hard to use where inward pressure against the spring was needed. It went away.
I recommend trying down tube shifters. Presumably you have down tube bosses and so you can go Dia Compe friction or Dura Ace rear indexed routes for about the same money. Your STIs will still work as the fine brake levers that they are. FWIW I much prefer friction - less faff and works fine on 10 speed if you grew up with friction.
General cycling advice ( NOT technical ! )