Girl already married now married me by fraud what can I do

I met a girl online and married her after she convinced me that her parents will not agree to our marriage. She never introduced me to any of her family member. After seven years of marriage I have come to know that she is already married with one daughter and her first husband works abroad. She had been going to her first husband on the pretext that her father is severely ill. I had often fought with her on going to her parents house as she tells me I am not acceptable to her parents. Whenever I tell her that I will leave her ,she threatens me with suicide. Please advise what shall I do .