On my phone, (a samsung droid charge model), you go into the main menu, hit the settings button and it's pretty simple to disengage the GPS.
I'm sorry your family is not taking you seriously. It might be time to stop keeping up appearances to them and your friends and simply state to them that you are fearful for your physical well being and what steps you are taking. Don't wait until he escalates and someone asks "why didn't you tell anyone" standing over you with a broken arm. I would also report the pizza man incident to your attorney with the exact date and time. if it sounds silly now, it won't if God forbid he tries to hurt you again...don't worry about his bite mark and how it sounds, he forced you to it by not letting go of you.
you are never going to change the way your mother thinks...but telling her how you are dealing with it and not sugar coating it may get through to her.
you don't need this push-pull emotional drain every day. Take the kids and go early if you are taking a new job in a different state???? what does your attorney say about this?