My boyfriend Is bipolar and it scares me :/?

My boyfriend and I have been together for 8 years I love him more than anything but he is bipolar and scares me. Always threatens to pack his camping gear and go live in the woods when things get bad after screaming and being crazy I'm so confused to why I cant just leave him but I live him. He wont take meds says there trying to control him. Everytime he has an episode he shaves his head will he ever get better? My sisters boyfriend was Also bipolar and we would compare stories but one year ago he shot himself in the head cause she called the cops on him! Could this happen to me? Why can't I walk away???? Am I sick to?