What if my wife has been cheating on me?

Ours was typical tamil arranged marriage .. for about 1-2 years frankly I was depressed she wasn’t any match to me .. had insulted her sometimes also ..but also good took care of her ..then we had a kid, after which I started loving her like hell ..but once when she was in her mother’s house after delivery I gave her a surprise visit one day .. I was working 400 kms away but came in without telling her .. we were talking inside the house ..there was no one at her home ..then her cousin’s bike sound ..and strangely she ran out of the house to tell him that I had come home suddenly ..which kind of made me suspect her a bit .. I asked that directly to her as to why she acted like that ..and we had some fights over it .. on and off .. meanwhile our son started speaking ..and my love for her grew unbound .. every day and night was fun ..but me being a software we only had sex in the weekends .. then a cousin of mine 19 years old had come to attend a training in my city and stayed at my place ..for 2 weeks .. he was 10 years younger than her .. I started seeing some suspicious things at home ..a bit long to describe here .. I then confronted this guy directly and bet him a bit too ..on which he confessed my wife had been visiting his room in the night all of 2 weeks .. asking him to have sex with her when I was deep asleep .. she also had been hugging him kissing him with me just meters away reading or watching tv etc .. anyways when I asked her she made big scene that I lie he lie etc …

she is at her mom’s place and now our families are talking truce treating the whole affair as just my suspicion .. the cousin guy also now refuses all he said ..what should I do now .. I am 200% sure she had sex with him with me sleepign in the next room ..