Is the restaurant insurance company liable for my injury costs?

After talking with the insurance agent, I feel that she was being truthful. I bit into the stem of an avocado, which I assume was mixed into the guacamole included with this en tree. I have had jaw pain/headaches/sore teeth everyday, where I bit, for over 2 month. I went to the dentist, had an x-ray, nothing broken. The dentist told me it was likely bruised. Restaurant manager suggested I had nerve damage. I avoid chewing on that side of my mouth and have avoided eating anything crunchy or hard, as even eating a few Fritos will cause a pain flare up. I did not have this problems before biting in to that stem. I have also tried massaging the area, icing it, and pain medications. The insurance rep told me that because it is part of the food, that they are not liable or responsible. She compared it to an orange seed. (Clearly, a seed is INSIDE the orange, but a stem is not.) But because I was "such a nice lady," she offered to cover the one dentist appointment (she winced at the cost), and a follow up, provided that would be equal to or less than the cost of the first appointment, and provided I get the info back to her within a month of it being reported by the restaurant to the insurance company. (Lots of stalling on the part of the restaurant and the agent took over a week to call me.) It seems wrong to me that they aren't responsible in any way, and the rush on the time to get papers back to the agent seems suspicious, telling me I get it back to her by the 29th, or they won't even cover the initial dentist visit. (The restaurant told me to go right away to get it checked out.) What can I do to get them to cover costs and future costs (if any), and don't they have to cover some amount for the pain I've gone through? When I was served food at a restaurant, I trusted them to serve me food that would not hurt me! I've never had a problem like this before, and I thank you for your help.