Back/chest pain was one of my first symptoms, within 3 weeks of insertion. I am still dealing with it today, 6 months post removal. Some days its there, some days not. I also have the jaw thing as well - feels like my face is stiff, like my jaw doesnt want to move right... its a weird sensation and I am painfully aware of it when I talk to people. It also comes and goes.
I would remove it asap. The recovery is long, but leaving it in has got to be worse.