School authorities are Forcing me to resign or terminate

I am wirking in a school as a tecaher.an anonymous letter came to my school that i used to visit oyo hotels with a school teacher..without any proof thay forced me accept it and said to write a resignation.when i did not do the same and talked to chairman also..they finished that matter But now school prncpl and vice prncpl are forcing me to resign and saying otherwise they will terminate me as saying that parents are complaining against your teaching.they dont have any kind of written complaint.students like me there. Plz guide me