Seeing a tmj specialist is advised.
Get you a night guard, go to the Pharmacy and ask for an over the counter night guard. My dentist made a nightguard for me. And yes it does help with you teeth hurting, neck and head. Try Synesodyne toothpaste, that will stop the pain in your teeth. As far as the neck, head and specifically shoulders go to a Massage therapist and tell them to work firmly on your back, shoulders neck and head. Be sure to drink a lot of water after the massage. But the next day, sometimes almost immediately, you will feel relief. I'm surprised the dentist didn't suggest a nightguard or synesodyne toothpaste.
Good luck