Hello and welcome to FF! I'm very sorry about your toad . From description it sounds like a broken backbone. A visit to a herp veterinary and a xray can provide more insight into the amount of damage to spine and also to toad's internal organs. Toads and frogs have good healing abilities; but if spinal cord is broken, it's health is probably going to deteriorate and it will die. The fact that all legs are unresponsive points to damage close to head.

Hope it's not necessary; but if his condition deteriorates you might have to consider euthanizing toad. Applying maximum strength Orajel to toads belly will euthanize it without pain. Keep us updated on your decision and good luck .