I m 45 yrs male married since 16 yrs My wife 40...

I m 45 yrs male married since 16 yrs My wife 40 yrs I caught her cheating with me she is in love with her school classmate. in absence of me they are calling each other n have good relation in social media Two times I caught her doing so sheasked for sorry she will not repeat it but I still he called to her in front me ( to my wife) I m undergoing lot of hot argument she told that it is nothing everything finish But I m now not believing her Now I m feeling alone m shattered I m not able to conc my job n nothing interest in life I m not able to sleep properly Whether I have to finish my. marriage or stay separately I don't know anything She is maintaining a grp of her classmate On social media What i will do wether take divorce or to separate Or how to punish this type of wives Please help me out for the same. According to sharia Thanks