Placed mangalsutra around my neck, got into physical relation and got me pregnant

Hi, We're both Hindus. He placed a gold mangalsutra around my neck, stayed overnights at my place regularly, purchased saris for me, paid grocery bills occasionally, maintained physical relationship with me and got me pregnant. I believe he is my husband as he told me himself that we're now married. But he later forced me to ingest some pills against my free will and caused a miscarriage. I have hospital reports of the pregnancy and miscarriage. He also admitted in court to placing the mangalsutra around my neck although he made me delete our pictures earlier forcibly, but falsely states that it was just done to fulfill a sexual fantasy. But I have text messages of him admitting placing the mangalsutra and also official court transcripts. I also have text messages from him forcing me to get rid of the pregnancy at that time, before the miscarriage had occurred. He's a male of above 25 years of age, a Telugu guy and is a Brahmin. I'm a Reddy. He's of sound mind as well. Would our marriage be considered valid in the eyes of law? Can I go to court and claim that he married me? Can I openly say that he is my husband? Can I change my last name to his's? Any helpful answers will be highly appreciated. Thank you very much!