My jaw hurts when i open my mouth wide?

Joint: It is the temporal mandibular joint that can get inflamed or tight from biting down too hard on food or grinding your teeth at night that places it out of alignment that may be giving you the clicking sensation .If it starts to hurt you should have that evaluated.

Probably TMJ: Probably a jaw joint (TMJ) disorder. Could be other things. See an oral surgeon for assessment/treatment recommendations.