T,
While you wait for the union to respond, get some rest.
Remember that if you were unfairly terminated, a lawyer can help, if you can find one suited.
A good attorney will get you what you deserve.
When the smoke clears, you'll realize that the two administrators are not personally upset with you, since if that school is poorly rated, they are just trying to keep their heads above water. Even if you were the best teacher in the state, you couldn't salvage a bad school's reputation, if it is that bad.
There's a short book by Robert Sutton about civility in the workplace, so you might google this Stanford University professor's name for the title, which will probably be deleted, but I'll try to post it. It describes the toic workplace concisely, so you can understand, as most who have been in bullying situations, that it's not you, but the situation.
Read "The No ******* Workplace" by R. Sutton, and you'll realize that not many people would survive your situation as you wait for the union and get legal help.
Take care for the time being.