Husband threatening me to give divorce.

I am married for 8 years. My husband has an affair since one year. In Aug he left for Dubai and resigned from his work and is in mumbai now. I came to Mumbai in Aug and at that time he informed my family and me that he wants space. He now has sent an email asking me to for a mutual divorce. I do not want to go in for a divorce. He is then threatening me he will take legal actions. I wanted to know will us staying separate make it easy for him to get a divorce. When I came to Mumbai and went to his place he threatened me he will call the cops and put a restraining order on me. Please Advise.