Wow, now that sounds horrible! I do know that if you think of rubber bands. There is a huge rubber band that starts at the top of your head, goes down your head, down your back, through your glutes, down the ham strings, down the backs of your calves and then down to through the ankle and heels. This is a rubber band that never gets stretched. That whole area can work together. Bad issue in one can cause issues elsewhere. When you have extremely tight hamstrings, you normally have low back pain, etc. Pain pills and muscle relaxers are probably not a great answer at this point.
You should see your doctor but yes, anxiety can cause body wide muscle twitching. Other things to be mindful of is hydration. Dehydration can also cause this.
The serious thing you can watch out for is dystonia. But . . . that CAN be brought on by stress. https://www.webmd.com/brain/dystonia-causes-types-symptoms-and-treatments#1
So, I would definitely speak to your doctor and hope you come back to tell us what they say.