Laugh/yawn really hard my jaw gets locked it's on the bit between the neck and chin it feels like something is getting stuck it's hard to describe had it for a while i grind my teeth out of anxiety alot and there's no pain? i'm very worried about it?

I suspect that your temporomandibular joint is tight from chronic stress and this causes cramping of jaw muscles when you yawn. It's like a charley horse in your leg. An oral surgeon can evaluate & advise you. Stress management therapy. should help alleviate chronic stress and/or anxiety.

You probably have a disk in your jaw joint slipping out of position. The cause may be parafunctional habit (grinding). Ask your Dentist for referral to a Dentist that treats Temporomandibular joint dysfunction.