About the son's illegal affair

Respect law professional's. I am a 56 year old widowed women having 4 children. My daughters are married. My two are educated well and settled in life. My husband died in 2012. We were trying to set marriage to my elder son of 38 years aged, he keeps on rejecting the marriage since 2010. Even after death of my husband he still refusing. In 2013 he got a government job as teacher and after a year we asked him to get marry now, even your brother has to get marry (28 years old) but he keeps avoiding the proposals. In the year 2014 he just got mess for unknown reason and he hit me and my younger son. He demanded a portion of house to live. We were living combined but due to the harsh behavior me along with younger son moved into ground floor (previously given for rent). It's been 10 months we are living apart. Before a month he again started to harrass me and my younger son to partiate the amount which I got after my husband's death.(gratuity amount ). He says you both should leave the house and live somewhere else.. we are very bothered about the situation. That my own son is torturing me and younger son. We were in dilemma that why would he need the house and and money. Although he is employed. But later on we came to know that he is having an affair with a women (Muslim) where he work. For that women itself he is doing all these harassment to me and son. A week ago he threatened me to leave the house and hand over the Jewellery that I owned. some of my relatives say that he had married that women last year itself and kept secretly. That is why he keeps missing late nights. We didn't not know. Even my younger son inquired about illegal affair of my elder son with women came true. Now in this dire situation what step should I take to get protected by my elder son