Divorce after 15 years of marriage

I have been married for 15 years now and we have a child aged 13 years The marriage was troublesome from the very first day but i didnt have the courage or the maturity to decide what to do and societal pressures and fear of being ridiculed forced me to stay on. Intervention of both sides made it worse and even after so many years we still fight for old issues Other problems i face due to my spouse : 1. Greed for money 2. Always seeking materialistic things 3. Cant discuss anything with her like a companion 4. Always accusative of me being a pervert 5. Blames me for her failures Issues that i have ( self realisation) 1. Not very ambitious 2. Irritable 3. I drink and smoke but not the extent that i dint look after my family 4. May have long term commitment issues 5. Might have started to look upon other independent women who are confident And self dependent I want to part ways peacefully with my spouse But take full responsibility of the looking after my childs education and My wifes basic needs. Now problem is that , her basic needs are excessive. Both are equally responsible for the unhappy life. I stuck around for my child since she is not to blame. But over the years, she has suffered and gone into a shell and become a shy and timid personality I want to quit for better or for worse Fwg Qs: 1.!how do i file for divorce 2. With a pay of 1.8 lakhs a month after tax deductions. Whats the maintenance and alimony i have to pay 3. Will this alimony include the childs education and personal needs since i am not going for fight for custody of child. 4. If i am ready to oay for childs education , personal needs like dresses and good life in college , will that entitle me to pay lesser maintenance 5. What if i want to settle it with one time payment ( will still support my child) whats the amount i might have to pay under bOth options. One time and monthly Pls advice