Take who you have become with you. Don't let that go. Find other small town friends in your new area, keep in contact with your best friend and get a part time job as soon as you can. Pick something to study that has good remote work options and if you have truly fallen in love with small town living, then go back to it when you are legally able to and can support yourself doing it. Your friend will probably love coming to visit and you can visit them on the holidays if you have your own cash. Look at this as a temporary thing that gives you the best access to education that you can make work for you wherever you go in your career path. Your parents are doing the best they can for the family, accept that but it's only until you can make your own choices. So, build towards the future you want with the resources available to you and then go live the life you want. Small town living is wonderful if you are suited to it and it sounds like you are so there's your direction. You just need a decent, solid foundation under you to make it a stable future. Deep breath. Being away will last for an eternity but it will be over in a blink once you get back there.

Once you are old enough and able to, move back and watch them complain about it. (Obviously see if you can get a job there first then move.)