What Causes Fatigue And Hand Tremors On Intake Of Benylin?

Hi, i had a cold this past friday and it has gone away now, but during saturday i had 2 tablespoons of benylin recomended dose and the bottle was then empty, in the afternoon i had another benylin bottle but it was a different kind, and used the 30ml cup thinking it was the same 2 tablespoons but it said teaspoon, and later that evening using robitusin extra strenght thinking it was tablespoons aswell foolishly, 30ml instead of 10ml, it is not tuesday and i have fatigue loss, but only mildly if not at all noticable, but the main concern is the muscle buzz, and slight shake of the hands hardly noticable aswell, that saturday night and sunday, my muscles felt like they couldnt be satisfied from stretching, the urge to stretch would come back every 5 min more or less, i dont get that urge now but i can only assume this is some kind of withdrawl, help would be greatly appreciated.