You win some, you lose some. (Ok, so some of us lose more often than winning and vice versa).
Perhaps she left because she didn't think you're the right person for her. That doesn't mean you did anything wrong or should change your personality to match her wants and needs.
So, cheer up dude. Rest assured, most people have had similar experience.
I also just broke up with my girlfriend of 1 year recently. I must admit that I was the one who did the dumping. She was nice and very pretty (a very, very delightful face to behold).
But, after a year, I just didn't feel that we were clicking. She needed a nice homely mellow guy who can be there 24/7, while I have this craving ambition to start my own business and accomplish something more in life. She always wanted more time from me, and I always felt that I'm just letting my goals and dreams slip by when I end up spending my entire weekends (the only personal improvement time I have from working as an employee) "chilling out" with her.
After a while, I just felt too tired to even talk to her. She gets upset, I get annoyed. So, I pulled the plug before this thing turns for the worse.
Somedays I think I'm making a serious mistake. Yet, I wonder if I'm just being a bit shallow since I'm more attracted to her wonderful looks than mutually compatible personality.
On the other hand, I'm also a bit replused by some of her family members - namely a jerk of a dad who flirts and who pretty much leaves her family to fend for themselves, but wants to marry off his daughters to rich people. Which, makes me a bit uneasy because I come from a well to do family. But, then I'm essentially penalizing her for her dad's flaws. This is all too complicated for my brains.
Well, I suppose I'll find out if I made a mistake someday.
Great, this has somehow turn into a theurapuetic rant.