I am glad you ask because it is important that you make your own health your first priority.
Joanne already made some excellent points. During some classes, it is almost impossible not to participate for the entire time. I would recommend not to do more than 10 of those per week.
But you may also be able to place less stress on your body during other classes. If you teach sculpting classes, you can go with the lowest weight you can find an focus more on teaching and walking around than actually participating. Adding core classes are another opportunity for little participation, and I can tell you from my own experience that people really like it when you walk around and correct where necessary.
I also love Joanne’s point about having (or not) a microphone. Voice injuries are very common when you feel compelled to yell for cueing. I actually purchased a personal microphone system where I carry the amplifier around my waist if I ever find myself in a place where my voice needs extra help.