Im not an MD... BUT....
You may have DIABETES Type 2. Do you suffer from the following (in addition to the shaking):
Cold sweats
muscle looseness in the back area
Extreme lack of energy
Usually you need to boost your blood sugar QUICKLY when you get hit by this.
Oftentimes, Diabetes 2 can be treated through lifestyle changes/dietary changes.
http://diabetes.about.com/od/diabete...w/a/whatis.htm