Divorce case after 18 yrs of marriage

Dear Advocates, I have got married around 18 yrs back. my marriage was not that good because we used to fight each other often. Around 7 yrs back, I have got a job in Nigeria and i left this country and were visiting India once in a year for 1 month. My wife and kid was also were visiting Nigeria once in a year for 30 to 45 days. Before I left India, i came to about her affair. I tried to check with her but she has not accepted anything. After i left, she had affair with one other guy and it is still going on. I have doubt that she got pregnant twice with him. I am tracking her chats and i came to know that this affair is since last 7 yrs. in chats with her bf and her sisters she accepted many times but if i will ask, she will not say anything. She spent a lots of money on him as she was keeping all my bank ATM and cheque book etc. Now since i have evidence of her chat and her pics with her bf, can i file a infidelity case against her? One of my friend suggested me to file case from Nigeria and since she cant come to Nigeria for fighting case so after 3 hearing court will give decision in my favor. is it true? Moreover I have 2 properties. in one she is co-applicant while in another property is on her name while i am paying bank loan. Currently i am in India for 2 months. Kindly advise how to move ahead to get rid of her now.