This began happening about 5 days ago. The left side of my jaw felt like two bones began rubbing together and then slowly snapping when I tried to bite down. It's not a "click" feeling, but a deep "thud" as the snapping occurs. I discovered a hard circular bump about the size of a dime right under the left earlobe where the pain occurs in my jaw. It sticks out visually. I don't think the bump is acne, but it could be a coincidence.
Today, I can't bite down properly. The left side of my teeth do not close together anymore. It feels unbalanced as only my front teeth on the right side are only coming into contact now.
This might be a possibility - right as I began these symptoms I started using Listerine Whitening Expressions mouthwash. But it could also be a coincidence, too.
There is also a possibility that my top metal retainer that I wear at night could have been bent.