It would be pretty unusual to do permanent damage to your jaw with something as simple as biting down on a piece of candy. This would be more likely simply to chip a tooth. However, it is possible that you could have strained or sprained your jaw (which would involve the temporomandibular joint). I sprain to this joint would feel a lot like TMJ pain
syndrome. For example, you may have trouble opening your mouth all the way or you might have pain with chewing or opening the mouth or you may feel a 'popping' sensation when you perform these activities.
If you have any of these symptoms, you should get in to see your primary care doctor
or your dentist
. They will be able to perform an examination to see if you have any evidence of involvement of the temporamandibular joint. They will also be able to determine whether you otherwise did any damage by biting down on the candy (for example chipping a tooth).
In the meantime, you should try to rest your jaw - avoiding any hard foods or vigorous chewing until any symptoms you have subside. Anti inflammatory medications like ibuprofen and heat or cold to the area may also help.