My husband was already married and he also marry me.

I got married in 2019 with Christian rituals and in 2021 I came to know my husband has one more wife whom he marry in 2016. I have proof of the marriage as well. But when I asked he told me it was not a legal marriage, I was forced to get marry... Except this he also have extra marital affairs and physical relations with many girls and married women's.. After our marriage we both were staying at my parents home in uttarakhand because of my job.. And here I caught him with a girl so we have so much of fights and all than one day he called his parents and they took him to there home in Punjab on 3rd feb 2022 and from that day he didn't came back till now.. I also have a son of 19 months.. nPlease tell me on what basis I can file a case on him.. Someone told me that the court will not accept your marriage because he is already married and you won't get any mantinance.. nPlease tell me what can i do. How can i get divorce and maintenance for my child?