The first thing I would advise you to do is to look in the mirror and see if your teeth have a very flattened appearance. Flattened teeth are indicative of teeth grinding at night which is a common cause of jaw pain or jaw locked symptoms.
Nocturnal grinding ie teeth grinding during sleep can increase in intensity especially during stressful periods which can lead to heightened pain symptoms such as the ones you have described.
In general, the underlying reasons for jaw pain can be split into 2 categories:
1. Muscular and soft tissue issues
2. Skeletal (bone) and hard (teeth) issues
Solutions for a jaw pain can be as simple as a nightguard or something more advanced such as painkillers / botox / orthodontic treatment, in order to get to the root of the problem and get you pain free in not just the short but also long term.
A full consultation with clinical examination and xrays would be needed to determine the reason and solution for your jaw pain.
Hope this helps and feel free to inquire further! Have a great day ahead.
Regards,
Dr Beth
