Average break up time?

This is for everyone. My boyfriend and I broke up a month and a half ago. We were together over 3 years, and have never broken up before. What is the average break up time? 3 months? 6 months? I love him so much and I know he loves me, we were just going through a stressful time and I feel like we were meant to be together. We were just talking about getting married next year...we separated because he said we were in different spots in life. And he said I was perfect and shouldn't change. He also looks miserable at work most of the time, and I know he's seeing someone, so shouldn't he act happy around me?! confused..average time for a break up?! Anyone please?!
Average break up time?
Post Opinion