Extended Sick Leave / quitting FT Teaching Job

I’m having personal health issues and my doctor strongly suggests I take an extended break in order to pull myself together. Also, my job is sucking up about 60 hours a week most of the time and I really think (in time) I should just go back to part-time teaching. Don’t want to stay at current job, even if offered part time hours. Very bad management. I’m willing to struggle through until the end of the semester, but not for winter/camp/ CNY. Contract ends next September.

I’m having a hard time figuring out how to wrangle this. When I offer a doctor’s note, explanation, etc, are they going to expect a resignation or fire me? Are my reasons for leaving going to turn up in some sort of record that my next employer can see? Not sure what to do. Am I going to end up doing a visa run? Any way to keep my health insurance?

Thanks in advance.