Get a Cease and Desist from a lawyer. This person, like all left antagonists, are weak people and only thrive against soft targets in environments that put up zero resistance. It's highly likey that as soon as he served that letter, he will back down.

If he continues, sue his ass into oblivion; you will still be in a school with a new vehicle and a lump sum in your account ready to put a down payment on a house courtesy of that nut case.

You will have the last laugh!