Fraud,cheating by stepmom's family hiding about her lunatic and sadistic nature and mental illness

Respected sir, After my beloved mother's demise at my age of 21 years, my dad remarried again without my consent to a lunatic and abusive lady who was 55 years at that time.Her family hid about her mental disorder.She doesn't have any children.She's barren since young age. Ever since his marriage to that woman i was completely abandoned by dad and disowned by so called relatives.I was severely illtreated and discriminated for no reason.she's been verbally abusive,energy vampire and threatening with very high pitch and sadistic in her behaviour..No support from father or relatives morally or financially towards my career and dad also became manipulative and deceiving. Dad became puppet in step mother's hands.Still i managed to write IELTS and got admission in Australia twice but dad gaveup at last moment and lied he doesn't have property to sponcer me(But there was property of my grandfather and own mother). I used to eat at temples and do meditation in meditation centers to escape from her abuse and disturbance at home for many years.I was helpless and in severe agony. I picked myself up from the trauma and attended interviews and now earning myself for a living. I have ancestral property of my grandfather and mother.My father sold my mother's property for his own use. Grandfather property is remaining.My father is refusing to give me that. Sir my main question is, can i sue or file a complaint against step mom for causing me mental agony and trauma for many years and doing defamation and false allegations and controlling my father from supporting me? Is it possible to sue her and her family for the trauma,loss and damage they did to me?