Karen is right, start with the agreement.

then do the following.

Let her know first, then install a lock on your room.

Unless you both are working 7 days a week, find time to meet with her. Do it at her convenience.

Take pictures of all of your things so if something else is damaged you have evidence for small claims court.

If he ever calls again like that, do one of two things. Either hang up on him, or record the conversation (as always, be civil and say something like "my lawyer recommends that I record all phone calls between us now so I will be recording this call)".

then get the H**L out of that place!