Hi Ayame,
I too am a teacher and the first few years are tough. I would suggest attending a meditation class or retreat to learn how to tame your mind which, at this point, is causing needless angst. Yes, there are always things to worry about, but it’s our choice how much to let this dominate our lives. Anxiety is the mind working overtime. I would also check out Youtube videos by Eckart Tolle and Pema Chodron. Very helpful to me. Hang in there. Hugs!