Mental and physical torture by husband and inlaws

I am in a religion Muslim and married back 8 years .after 6 month of marriage different types of torchure has been taken place from husband and inlaws like recording our privacy night-time.Installed camera in my bedroom and all male inlaws has the access of it .sister in law's husband have a bad intention to assault me and outrage my modesty by saying unacceptable words removing his shirt infront of me and trying to hug me.husband and inlaws asking for dowry everytime from my parents my father is a retired person and mother expire.everytime forcing me to bring money from my house .husband has an affair with elder brother's wife. I have one child 6 years old even he is suffering from mental and physical torture my husband's elder brother and his wife abundantly hitted my son badly I have the video footage and when I started objection they had beated me and so my husband threathen me that if I go for legal then he will share my private video in the porn site and thrown me out of the house and put me in a high rent where me and my son resides and husband resides with his family.Now when I refused to entertain him with money anymore so whenever he comes to my rented house forcefully does abnormal sex which is prohibited in islam.please guide me what shall I do to protect me and my son from this people.thank you