Unpaid 3 month salary and 8 months provident fund

I am working in a private school affiliated to CBSE situated in ambeedkar nagar UP from around 4 years. During the first two years my name was not registered in their main attendance register and during those time i was signing in a secondary register which they used to use for the atten8of non permanent staff. But from 1st april 2019 my name was registered in their permanent register and since then i am putting my attendance in the same by signing daily (i was not given any appoointment letter too). After the corona pandemic school has not paid any provident fund in my PF account since may 2020 and three month salary is still hold by them. Now a days school principal has started to harass me, intimidate me on the grounds of bad performance and putting more and more work load on me so that i could not ask any appraisal. In such a scenario can i negotiate feerlessly with the pricipal regarding my appraisal as three month salary and 8 months PF is still unpaid by them. Can she terminate me without paying my old dues? I dont hold any B.Ed. degree can this issue work as a negative point for me? Please enlighten me on these critical complications.