How can I stop my jaw from popping?

I need some help, please. does anyone know how I can get my jaw to stop popping? I have lock jaw, and my doctor said the best way to help is to get braces, but I don't have the money, and my insurance won't cover it. every time I sleep on my side, it gets worse, or my jaw pops just from opening it, and it's getting to be a pain (literally and figuratively). thank you in advance!