Hello,
It could be carpal tunnel, or a type of nerve entrapment. I suggest seeing a chiropractor, I have had similar issues, mine adjusts my wrist and it feels so much better. Also, while healing, try wearing a wrist brace and at night, soak it in some Epsom salts, the magnesium will help with any spasms that might be present.
Can try wearing a wrist brace that keep thumb less mobile.
Also, coconut water high in potassium.
Make sure your vitamin D and magnesium blood levels are good
Will try the bananas.
Nerve entrapment. Is there likely source, elbow, shoulder where there might be stretches, exercises to stretch out?
It could be nerve entrapment, but more likely potassium depletion, which sometimes cayuses these aches. Try eating a couple of bananas.