New workout program abt 2wks. w/in a few hours after, have tremors in hands, uncontrollable, very pronounced twitching/restlessness in whole body. lasts until i take my ativan and (although i eat right after exercise). what could cause this?

Post workout: Are you eating prior to the workout too? Make sure you are not dropping your blood sugar too low. Also, are you taking any other medications or supplements that could be interfering with the blood sugar? Diet supplements or such? Has this happened to you before? I would try to get evaluated by an M.D. for some further testing. Good luck!

Get checked: Muscle fatigue can produce abnormal twitching - and may improve with stretching and hydration modification of workout, however would be very important to have tests run by a doctor to exclude hypoglycaemia (low sugar) and electrolyte disturbances which need to be treated promptly Please see a doctor licensed in your area for evaluation +/- tests.

Can be normal: Quite a few folks have this especially when they're doing conditioning. It's a sign you're working hard and you should be proud. Since you're under a physician's care, if this does not resolve as you get more conditioned, discuss whether you might have familial tremor (treated with propranolol, perhaps), a channelopathy (get electrolytes checked) or get a neurology referral. Glad you're exercising