False allegation on extra marital affair

Hi there, I'd an arrange marriage with my wife 4 years back. Early months of my marriage were quite happy and good but then my MIL started interfering in our every single decision. Before our marriage, I have had told my wife that i had dated this girl but we broke up and i've not been in any contact with her since. My MIL advised my wife to look into my previous relationship and talk to my ex-girlfriend if she knows that I'm married or not. Also, If I'm still dating her and cheating on my wife. Regarding this thing, I had zero knowledge on what's going behind my back and what my wife is doing. After few months, My wife confronted my ex-girlfriend because someone shared our old pictures back when we were in college with my wife and told her I having extra marital affair. My ex who was confused at the moment, accept we dated in past but have no history in present after my marriage. My wife was pressuring her to accept that we were still dating. My ex got furious with all these thing happening all of sudden and end up contacting me asking me the same. My wife heard me talking to her as we were in same room. I was also furious with my wife why she has done it and afterwards she got angry that i picked her call and she called police on me and my family and filed a dv and extra martial affair case. What should I do? we have a beautiful kid together and in between everything i was not able to see her for past 3 years. Will old pictures also counted as extra martial affair?