Is my marriage Valid? Will I get justice

Hi Sir/Ma'am, I am a Hindu girl and got married to a Hindu guy(same caste) on 10th March 2017 with the support of both the families and marriage happened as per the Hindu rituals. It was 100% arrange marriage. After six months of our marriage, his father gave me a no and asked me to enquire about it(not sure if they were knowing it before). He just said that a girl calls frequently on his no(on my father-in-laws no). When i checked it was a girl's no and she claims that she is the first wife of my husband(they got married on 22nd Feb 2016) according to her and also she is a christian by religion. But my husband says i didn't marry her ,we are in relationship for past 10 years and I can't leave her. You adjust with this constraints. Though he didn't disclose all these facts before our marriage.He says she will not come into your life, she will be in other city. I will stay with her 15 days only in a year and rest of the time I will be with you. I strongly denied this proposal and he abused me like anything for not accepting all these. Even his sister supported him and said that he will not leave her, if u are ok then stay with him otherwise give him a divorce. Even his father says that because he got married her so he won't be able to leave her so if u can manage to stay with him then stay otherwise we will search a new match for u.Many things happened in these almost 3 years, that guy slapped me, abuses me badly, demands for money every time I go home. I tried collecting proofs of their marriage and could got only their whatsapp chat messages where they wished wedding anniversary each other. Also I have call recording where he has accepted that he has done two marriages and also I had chat with that girl where she says that she is his legal wife. Now I have many doubts here 1)Am I his legal wife? 2) If I file a fraud case against him, whether the proofs I have now will be sufficient ? 3)What action can be taken against his family to trap me? 4) If his first marriage is not proved, he won't get any punishment? Request you all to answer my queries and please suggest me what Can I do at this point in time.