False mental illness case

I am a married working woman. Got married on Dec 2 2021. Due to the rising tension in the family and my workplace I tried to commit suicide but later decided not to die because I thought of my parents. I wrote a suicide note and left it in my room which later my husband found out. I was made to consult a psychiatrist and psychologist due to the problems that started after marriage. That Dr diagnosed depression. Now husband got enough reasons to leave me and is trying to prove that I'm mentally sick and that he could prove that it's all my fault and I don't want to maintain a family. He filed a case against me on June 2022. He also asked for compensation of Rs 25 Lakhs for hiding mental illness before marriage, even though I'm perfectly fine. I never had any mental illness and only after marriage we went to the psychiatrist. He filed for divorce on two grounds one is mental illness and other mental cruelty. He has photos of prescription from the doctor and my suicide note. Please tell me how can I prove in court that I'm not an insane person? Are evidences like suicide note and prescription of depression medicines sufficient for him to win the case?? How can I move legally against him for defamation as a mentally ill person? I have had enough. My family got humiliated because of this false case. Please respond with an answer.