Hi there, welcome to Healthcaremagic Pain coming from over-stretching the temporomandibular joint can be very severe and debilitating for a while. It will probably eventually settle on its own but the very least you need now is a good so-called non-steroidal (NSAI).
Other treatment options are a course of steroids
or, best of all, an injection of steroid into the joint space itself. You are going to have to see a doctor I'm afraid.
Andrew Rynne MD