The Argentina defender says he was prepared to quit his £3million a year deal and return home for family reasons.
Coloccini was persuaded to stay on for the rest of the season after talks with Alan Pardew.
He said: "I thought about walking out, but I changed my mind.
"It wasn't about the money. There were personal reasons but the club and manager have been great.
"I've been away from home for 13 years and I miss it. Now is about Newcastle United staying up... and we will.
"I love Newcastle United as a whole. I captain a huge club and I'm fully focused on helping to stay up."