First off, I'm glad you realize that your behavior is a big part of the problem--most guys never get that far.
An LDR in college is typically doomed from the onset. Any conflict in an LDR doesn't get resolved in the same manner as in a relationship that is comprised mostly of face-to-face time. It's a bit like having a fight with your pen pal.
That aside, your problem right now is that you've entered into a downward spiral: You know that acting insecure will make her leave you, which in turn makes you feel insecure. Compounding this is the fact that you have some serious ONEitis. But---who among us haven't been there?
The words you used early on to describe yourself (bad boy, dj, man in control) aren't accurate if you were motivated by your own insecurities in the relationship, and any attempt to control her at this point is going to be futile. Why? The cat's out of the bag--she sees that you need her more than she had thought. This is the consequence of breaking up with a girl and then taking her back. She's now likely re-evaluating all your past conflicts under this new light, and an unflattering light it is.
So what to do? You're going to have to either end or redefine the relationship on your terms. Otherwise, you are going to be dumped. She doesn't want to spend her birthday with you and would rather hang with her friends. That means you are no longer a top priority and she's starting to establish a new life for herself.
If you want to save yourself some heartbreak, call her up or go see her (NOT on her birthday) and tell her that you think you need some apart. Don't be angry, don't be bitter. Say that you care about her but you realize that the two of you are growing apart --and that's ok. Frame it as more of concern for HER instead YOU--you realize you made some mistakes, and you don't ever want to feel like you've "tied her down." Bottom line--be cool about it. This is the only way you are going to change her perception of you from needy and controlling to confident and understanding.
Don't count on this suddenly making her interested in you again--that's not the point--but count on it changing her perception of you. I'm personally very much against going back to ex's, but doing this will leave the door open for you two to get back together at some point. If she dumps you, this is far less likely.
The good news in all this is that as much as you feel that she is "the one," you can rest assured that there will be PLENTY of other "ones" in your life to come. You're going to feel bad for a little while, but it WILL pass, I promise you. In hindsight, even a particularly harsh breakup doesn't seem that bad. I know this seems of little use to you right now, but when you're young it's important to know that there's a light at the end of the tunnel.
ALL of us have gone through similar situations. ALL of us are now BETTER OFF BECAUSE of it.
