<human>: Im 27, shes 29. We'd been dating for four years. The entire relationship was rocky for a variety of reasons, and three months ago I broke up with her because I felt she wasn't the right person for me. 
Now recently, through emails and conversations, it's hit me that a lot of the problems I saw were caused by me. I had too high expectations, wanted the perfect girl that doesn't exist, and failed to show her how much I loved and appreciated her the entire time - and still do. 
She is heartbroken, angry and all that other stuff. I'm a mess, because I didn't even realize I was causing all this and I feel terrible for ruining and throwing away what could very well be a relationship that'll last a lifetime. I feel like I ran over any possibilities of true happiness before giving us any real chance. 
We are in different countries now, but if I put my savings together I can afford to fly in and see her for a day. I do not dare hope that she will ever be able to forgive me, because I really broke her heart, but the best I can do is apologize to her in person. I don't really know what will happen after, I just need to see her and tell her that I'm sorry I was such an idiot.  

My questions are, what else can I do to better the situation, and what can I do on a personal level to get rid of these expectations?

Condense the text into a few key points
<bot>: I put too high expectations on a girl I love and I ruined what could have been an amazing relationship. If possible, how can I get her back, and how can I get rid of these ridiculous standards?