Handcare from American Society for Surgery of the Hand
This is easy to read info. and explores some differential diagnoses for numbness of the hands.
Numbness in Hands: Causes & Treatment | The Hand Society


It is concerning that it is now your whole hand that is affected. Hopefully you get that appointment sooner than later.

Check out the Repetitive Strain Injury Sub-Forum

Edited to add a couple of things... Jomar suggested the TOS forum here. There is information in that as well.

and particularly the "Sticky" Thread there. Lots and lots of information. Look for stretches and tips for relief.

Here's the Search Feature
Thoracic Outlet Syndrome forum is listed above in Post #2 from Jomar.

Try a search in RSI and also Thoracic Outlet Syndrome Forum for specific keywords e.g. I just used "numb hand".