How Can I get divorce from my wife faster

I am 38-yrs, live in Calcutta with my wife (35-YRS) and 5 years old boy. My wife was model and presently home maker and occasionally do some ad / modeling/grooming related work. I have 8 years marriage life and we have very good relation. Trusted, loyal and still we are very much crazy to each other like honeymoon phase. Most of our relatives are very jealous due to our bonding. Recently I came to know, my wife had six years affair with a boy before marry me and were madly love each other and developed ultimate relation. They did some modeling assignment together. My wife broke up the relation with her fiancé because that guy develops multiple relationships. She confesses her relationship and says sorry for everything and request me to never raise any further doubt about her past as she want it all wiped out from her life. She is super happy with me and bury her ex. But I desperately want to divorce my wife at any cost due to her sexual past and I was virgin at the time of marriage. Although she gave me best eight years in my life with happiness, peace, love, joy and super craziness physically. I talked my wife, she is NOT interested. She is trying hard to change my mind and says she wants me in her life forgets her ex. But I feel very much insecure and affecting me both mentally and physically since February. In fact if we stay together rest of life, I cannot love her anymore.