Munroe had hoped to land another world title shot with victory over British super-bantamweight rival Quigg, but a sixth-round stoppage defeat dealt a massive blow to his future plans.
The 32-year-old came up short in his challenge to WBC champion Toshiaki Nishioka in 2010 and the Leicester man admits he is tempted to walk away from the sport if he cannot get back to the top again.
He told Boxingscene.com : "I've had a great time and a great career, but coming into this fight I've had to beat myself up to get up for it.
"My trainer [Jason Shinfield] said to me: 'You're losing, you're losing', and in the back of my mind I had it that I'd already told my wife and children at home that if I lost it would be the end of my career.
"When he said that to me, I think it just pushed the rod in a bit further and asked me: 'Look, do you really, really want it?'"
Reflecting on his future, he said: "I'm a fitness fanatic and I love to keep fit and stay in shape.
"I was training and getting fit for the fight but there's a massive decision between training for a fight and actually fighting. Is the spark still there?
"I'm 32 now and to get to where I really want to be and do big things, we're talking another two years. I'm gonna be 35 by then.
"I've had a career to be proud of. I've come from the bottom to the top."