Wife blackmailing for money. How to file for divorce?

Dear Concern i married to a Muslim girl just after my college but we both kept it mute in front of everyone and after 2 years we get seperated by burning that arya Samajh certificate and moved on in life , Then after an year I met one girl we both fallen in love and as trust and honest I told her about my past she accepted it and said no issues with the past but her family is not at all agree for her marriage as we both of different community , then one day she got run away from her home to be with me even then i said her please we both take sometime to convince your family but she started blackmailing me that if you won't marry me right now I will ruin the life of your ex whose already married then with full pressure n fear I married her , now she is blackmailing me every then n now for money for things and abuse me everyday with filthy words . Kindly suggest what should I do I'm really in a big mess .