Hummm, @saintgentle I would say, you actually made yourself went through the unnecessary ordeal, you tortured yourself as nothing was wrong with you. In my observation, the problem started while you were at your post graduate class, you retained the image of your Lecturer spitting in your mind, and the fear was there, so when your own students noticed that in you, the image of your Lecturer pumped in your mind and the fear came in.
I see it as a self torture, you should know that an average person talking for a long period of time can begin to spit, though that is quite different from drooling. Your best medication is self esteem and don't allow the thought to stay in your heart.YOU ARE OKAY!!!!!. Btw , you have a lovely wife there, she is so beautiful, my greetings to her.