I was diagnosed with AD/SD in 2005 in the middle of the school year. I have been teaching since then. I never considered not teaching because it is what I always have done and loved.Botox is a challenge because of figuring out when to get the shot. The down time with it can be frustrating.
Voice amplification is an absolute necessity. All our teachers have amplification systems. So mine is not an issue. However I recently replaced the somewhat cheap classroom system with my own system, which is incredible. It took some getting used to but now I feel more at ease than at any time since 2005.
I always start the school year by explaining what my situation is and how I will have strong days and weak days. I have students who keep track and will sometimes say, "you are sounding good today."
Some days I forget I even have SD. Those are the good days and there are enough of them to get me through the school year.
Good luck to you.