After reading this, I seriously whispered to myself "who's this girl?", hehe, don't get me wrong, I meant it in a fun kind of way.
I wouldn't say I understand what you're going through because I can never wear the shoes you've worn and men, its heartbreaking having your heart broken. I'm sure you were so in love with Mr EX, head over hills for one person. It surely is a wonderful feeling to love someone with everything you've got. I'm sorry MR EX was too blind to understand the magnitude of your love for him.
When you said 3years, sorry, I wasn't shocked because I went a good 4years without dating, Feels like yesterday. It's not what you're thinking, I didn't have my heart broken, no.. but my last relationship didn't go so well, I didn't cheat and all but I wasn't able to love. How do I put this?..I was negligent and didn't know how to express my feelings. So it didn't work out. Since then, I dreaded dating, for fear it'll turn out the same way, I didn't want to have someone hating me for no good reason.
So instead of force it, I left it, I know I'm not of a marrying age and there wasn't no pressure. But I took time to fully understand myself, took time to discover new things about other people especially girls, I made friends with them, I learnt to share secrets with them, we talked about deep things but I didn't let love set in.
Love is confusing sometimes, it's hard to understand. The right guy might come, but would you be able to receive him? .."He's like every other guy" would be the thought of the day. We just might never know how things are going to turn out.
Don't stop loving with your whole heart 
RE: WHY AM I REALLY SINGLE?