2nd time in 3 yrs as i recall i got this falling dizzy sensation and my body jolted when i was falling back asleep after getting up. my whole body just felt weird. and fell back asleep. lots of stress lately. no hx of seizures.on klonopin for anxiety?

This sounds like a hypnogogic jerks. They're strong, sudden, and brief contractions of the body that occur just as you're falling asleep that cause a sudden wake with a jolt and a jerk of the body. Hypnogogic jerks are common. Research suggests up to 70 percent of individuals experience these contractions. It isn’t a serious disorder. It’s unlikely to cause any complications or side effects.

Intermittent episodes of shock-like jerking can occur as folks fall asleep, and this can be a relatively normal phenomenon, but jerking in the midst of sleep, "Periodic Limb Movements of Sleep" is a pathological expression of myoclonus, and can disturb sleep cycles. Talk to your doctor about possible overnight sleep study to evaluate further.