Wayne Forrester told police he felt "devastated" and "humiliated" when his wife changed her status to single a few days after she had kicked him out of their marital home.
Appearing before the Old Bailey, barristers explained how Forrester was drunk, and had been taking cocaine before driving back to their home in south London and attacking his wife, stabbing her to death with a kitchen knife. He believed his wife had been having an affair.
Forrester pleaded guilty to the crime, and will now serve a minimum of 14 years.
In a prepared statement, Forrester told the court: "Emma and I had just split up. She forced me out of the house and then posted messages on an internet website telling everyone she had left me and was looking to meet other men.
"I felt that I was watching somebody else attacking Emma. It was as though I had no control of what I was doing."