3rd year hS teacher, 5 very different preps + night/weekend cert. classes. i'm worried i can't do it anymore.

I love my job, but I'm so worried about my health and wellbeing. Two years ago, I gave up an amazing job opportunity to go teach at my dream school (a magnet high school I've always admired), and after I accepted I was given more and more preps up until days before school began. The classes are all quite different and there's no set curriculum. Going into my third year, I was hoping I'd feel more grounded and prepared, but the grading load and other stressors are just building. This year, I also have to take graduate-level classes to get my professional certification, and I don't want to quit, but I don't know if I can actually handle it. I love the school and the students, but I need my health too. Strategies? Stories? Thoughts?