Opening a Dialogue?

So this situation has kind of haunted me for almost a year now...but some background info is needed...Sorry if this is long.

I grew up in a military town, but was not a military kid. I would say close to 75% of the kids that went to the same schools as me had parents in the military. As the military would move their parents around, the kids moved with them. So every year, at least one of my friends would move. And I'm one of those people that only has a few close friends, so I was close to anyone that moved. The norm was that the friend that was moving would promise to keep in touch, but as anyone that has had a friend move, or have moved away from friends themselves, knows that this is almost never the case. In my case, I never really heard from any of them after they moved. This whole situation has created some serious trust issues and minor abandonment issues for me, but that's not what I wanted to get advice on.

In high school, my best friend was a military kid, but was able to stay at the school for three years (the normal amount of time is two). This was one of those rare best friends who you can tell anything to, are completely comfortable around, etc. We decided to go to different colleges. And I got those same promises that I always got, that we would keep in touch with the only difference being that I actually believed her.

She didn't really keep the promise that well. But it was still a lot better than my other friends before who never even attempted. Her college was near where my family lives, so during Thanksgiving and Winter break (this was last year) we made plans to hang out. She was the only one with a car, so all of these plans consisted of her coming to get me. We made plans 4 times, and every time, she did not show up and never contacted me to tell me that she couldn't make it or why. I'm sure this wouldn't have bothered me as much if she wasn't my only friend. I didn't have much luck at all making friends at the college that I went to and I was looking forward to just hanging out with somebody. So instead of spending those breaks hanging out with my best friend, I spent them sitting around my parents' house alone. After she didn't show up the 4th time, I decided to try and cut off all my ties to her because she was really hurting me every time she didn't show and I figured that the only way to stop that hurting was to cut it off at the source. So I basically told her not to talk to me anymore thinking that I would eventually feel good about the decision.

One year later and I really don't feel good about it at all. She followed my wishes and hasn't talked to me since then. Like I said at the beginning, this has haunted me for almost a year now. I just can't stop thinking about it. I replaced the pain of being ditched with a different kind of pain that I'm not sure how to explain. I've gotten to the point where I think it might be better if I talk to her about it. You know, closure and such. But I'm not sure how to start any kind of conversation with her (I'm really socially awkward). I still have her phone number and have her skype info. I also had to transfer to the school she is going to and move back home because the college I went to was too expensive. I saw her there once, but avoided her completely.

So the question is...how do I begin a conversation with her? Or should I even try to?

How about saying, "I miss our friendship and I'm sorry"?