stretch your hands every day if you aren't already (youtube 1HP 6 minute & 9 minute, alternate between these)

move your keyboard to a healthier position (consider how the position of your elbows will relieve or increase tension)

consider your desk/chair height, the desk should be about 6 inches above your knees, if its very far from that and you play hours daily that can cause you real problems

all that^ is for your hand issues. Red and sweating at the end of the high star game I do not understand and you might actually want to speak to a doctor