Fake it 'till you make it: that sums up my entire career! You should, definitely, be proud that you've made it this far. I suggest that your health is more important than your students. I hope I say this with some insight. My daughter has been teaching for 15 years. You are incredibly dedicated. Yet you must take care of yourself. Do you have a psychiatrist or therapist? I can only sympathize (hugs) and urge you take as good care of yourself as you are of your students. I empathize with what you say. I faked caring for many years.