Mentally harassed by school principal and senior teachers

I was on maternity leave. Department had put a substitute on my place. One day substitute called me and said- aap 1 month pehle join kr lo school. Mujhe khi or join karna hai otherwise mere wha ki job nikal jayegi mere hath se. I said- abhi to mujhe 5 month hi hue h leave pe I'll complete my 6 month of maternity leave then I join. When after a month I rejoin my duty. Sabko behavior change tha even HOD ka bhi. Jab mujhe pta chal ki reason kya h sabke aise behaviour ka to pta chal... Ki mene substitute ko adjust kyu nhi kiya (tujhe join karna chahiye tha 1 month ago). Us din k baad se principal torture me at every time. Ki naukri se nikal dungi, higher authorities ko Likh kar de dungi hume teri need nhi h and all... Agar me 1minute b late ho jau to meri leave lga deti h. Jabki other teacher 2 hr bhi late aaye to kisi ki leave nhi lagti. Ek din sabhi employees ki meeting bhula kar mujhe sabke samne mujhe scolded me. Ek din school assembly me, in front of all employees and students Scold me alot. Reason ki tune computers kyu on kiye hue h, me ( principal) garmi me marti hu. Jabki Mene computers students ko practical krwane k liye on kiye hue the. Is it my fault? Kya me apne subject ka practical nhi karwau students ko?. Or ek senior teacher everyday said to me- " mujhe wish kiya kar (good morning or afternoon). Is it compulsory to wish any employe at workplace? I am totally meantally disturbed this kind of behaviour or school principal and a teacher.