Harassment from husband and his family

I'm married on Aug 2018. Generally like all other girls I'm afraid of first night. I'm an introvert by nature. I asked some time to prepare my mind for first night. But as per the tradition i stated with my husband and his family. From the day one itself my mother in law asked me to give birth to baby boy only. My husband's salary was 15k only.but they said it was 40k before marriage. Days went on like this. One day in the night my mother in law came to me and said n forced me to remove your bottom and sleep with my son.i disagreed by crying. The my father in law scolded me in bad words and threatened me to beat if I dont do so. I refused to do so. Then my father in law, mother in law, sister in law, and the husband of my sister in law, forced me to write a manuscript note that , i was forced by my mom and dad to for marriage. And they made me write by threatening many other things in that letter. That night was like a hell to me. Next day my parents came and took me to their home. Now I want justice. What should I do now. Please help me we are from a middle class family. Please help me.