Need Divorce but in a complicated situation

Need advice on what grounds can I apply for a divorce. I am married and have an 8 year old son. Since the past 2-3 years things between me and my wife have changed to an extent that we do not even have any physical relation. In this duration I started to have feelings for a different woman and she has been my strong support in everything, even for the current family. I wish to live with this other woman and end my matrimony with the current wife. I also wish to be able to meet my son once separated from the current wife. I no longer have feelings for her and since past 6 months have even tried hard to survive in this marriage. However, it is only getting me more depressed and my desires to leave grow stronger. I have had open conversations with my wife and about my feelings and a will to leave but she is still not coming to terms to that. I have left my MNC job and am jobless for the past 5 months. Please suggest as I can no longer survive with this matrimony.