I have been twitching, all over my body, for almost three years now. I went through exactly what you are going through (including the numb hands), with the ALS and MS scares and such. Please do not google twitching, as you will get these awful search results!
Twtitching can absolutely be caused by anxiety, but I also find mine flares up when I get sick or stressed out or when I am fighting a virus. I think it is just a defensive type of response that some people's bodies have. If you have no weakness or anything like that PLEASE PLEASE PLEASE don't worry that this is something serious. It is 99.99% likely not.
Do you have any back issues? Sometimes a buldging disk can cause twitching and numbness as sometimes they can pinch nerves.
I think you are gonna be okay