There is no excuse for her behavior, undiagnosed mental illness or not. Call HR. You do not have to stand by and just allow her to treat you that way.

Even tho you are looking for another job already, HR needs to know. If she is doing this to you, she most likely gas done it to someone else or will do it to someone else. Behavior like that from a manager is unacceptable, and most companies would either transfer her, give her more training or outright fire her.

Throwing things at you borders on assault, and in a professional environment, companies higher management and HR departments need to know. These are things that can get the company in a lot of trouble if it's not handled, but they need to know to be able to deal with it.

Please, call HR tomorrow. Preferably before clocking into work.