Do you have any pain in your jaw joint on the left side? You mentioned some dental issues which led me to believe you may be experiencing some TMJ disorder. There's a discussion board on here just for this disorder.
If you have dental problems or a bite occlusion these joints can often become inflammed and this can cause referred pain around the area, in the ear or even like a migraine.
I myself have tmj disorder and a major occlusion as well as acid reflux
. My jaw joints hurt daily and I often have burning, itching, stuffiness and sound sensitivity in both ears along with daily migraines. It's rough to live with so I know what your going through.
1000mg of Acetaminophen often helps with my ear pain, you might try it. If that doesn't work, try 800mg of ibuprofen. If either of these help, I would suspect referred pain from the inflammation of your tempomandibular joint.
It could also be that you have damaged your euchastachian tube, a condition called patulent euchastachian tube dysfunction. That's on the inner ear disorder board. But if your not experiencing any stuffiness I would doubt this.
Hope this helps!