It could be the lithium. I take it, too, and sometimes get the jerking when I go to bed or am resting, but it's not to the degree you describe. I would suggest you get your lithium levels checked, but since you're not on insurance, you would have to pay out of pocket for that. Can I ask how you got prescribed meds without insurance? It seems irresponsible for someone to do that without providing you follow up, especially if you have a history of seizure disorder.