Hi
Sorry you're feeling so sick. Have you tried supplementing with magnesium?
Also can sometimes be related to stomach acid issues. You could try googling that. Hope you find an answer soon.
I hope you are much more comfortable now, I did a dig around for info.
Here is a link to one PDF online I found. I myself regularly suffer with at least 30 mins of restless leg syndrome at night. Usually when I finally get tired enough to fall asleep it starts up. But unless I find out otherwise, it is not a tremor such as you describe.
http://essentialtremor.org/wp-content/uploads/2013/10/Leg-tremors-vs-restless-legs-syndrome.pdf
All the best to you.