Not weird at all, low magnesium can cause tremors, magnesium is major component of Epsom Salts, so by soaking them in it your absorbing the magnesium through your skin, so to get that affect on your body you could be just low in magnesium.
In supplement form, Magnesium lactate is the best type to buy, i would not waste my money on Magneisum oxide though.
If you have any kidney problems you must be a bit careful of to much magnesium, it should be monitored by your doc, but otherwise in normal people taking to much magnesium will normaly will just give the person diarrhea.
good luck
Aussie