The problem could be with your ear, your jaw joint, or even with your parotid gland which is the saliva gland that sits in front of your ear. I would recommend an evaluation with an ENT. We would be happy to see you at UK HealthCare. You can call 800-333-8874 or go online at ukhealthcare.uky.edu/appointment to request an appointment.
It could be a swollen gland try warm compresse or a heating pad, remember to place a light cloth between your skin and the heating pad. try the lowest setting.
I had ear problems growing up with the glands and what you describe is what I went through.
Is the knot behind and by the lob or in front below the cheeckbone? Or on the ear itself?