Rabbits are prone to back injuries and what you are describing is consistent with a broken back. Whenever you lift a rabbit it is important to grasp the skin on the nape carefully lifting and supporting the hind end with the other hand. Often, a nervous rabbit will kick and twist resulting in a broken back. Unfortunately, the only solution is to euthanize the rabbit. If you are comfortable doing it yourself, grasp the head while holding the body behind the neck, pull and twist quickly, sharply and with determination, unless it is an unusually large rabbit (which it does not sound like your rabbit) death should be immediate. If you are not comfortable breaking it’s neck, take it to the vet for chemical euthanasia.

Sorry-
Pete