@mariyadelano No idea for a good advice , sorry : i'm on the very lucky type oh hand that can handle the pen/stylus for ~10h per day without any pain.
Before the release of a new episode, I often go up in time budget, and in this case my hand muscle hurts and get tired. When i can't keep the rythme, I just do bath it in cold water, and apply various cream for sport before sleep. It helps. Sometime cream for tired feet too I had to do that last week for ep38, but i already recovered fully.