How to write a note to a teacher to make up work?

I am a junior in high school and I didn't complete or even attempt a large number of ignments in all of my cles. After the second semester, I completely dropped everything and gave up. I am being treated biweekly for major depression and some anxiety issues, and I've panicked about my grades and now I want to make up many ignments that have been due long ago. Since I don't have the confidence or can't find the words to directly talk to a teacher, I feel writing a polite note to them asking that I can make up some work may help me in my situation. I am extremely tense person and I know I would cry and go blank if speaking to any of my teachers, especially in a one-on-one conversation. I want to mention that I haven't had the ability to do some of my work without literally breaking down (this is the real truth) but I have a fear that they won't believe me and will see it as an excuse to make up work. How can I truthfully and effectively ask them to let me make up some ignments?