Rejection from NYU changed my life- for good and bad

Or I could say: Coming to UCLA has changed my life for the good and the really bad.

NYU was my #1 choice, and I would've attended NYU in a heart beat if they had accpted me. If I had gone to NYU, it's possible I may still enter the entertainment industry. It's also possible I would have continued on with my biology degree, and go the pre-med route to become a pediatrician.
UCLA was my #2 choice. Coming to UCLA has changed my life for the good and the really bad. Coming to UCLA, I found my "passion" in entertanment marketing (kind of by chance). I was able to have the whole "college experience." I grew up. On the other hand, if I didn't come to UCLA, I would have never met him. I would have never fallen in love, and I would have never had my heart shattered into pieces.

"She" seems to be perfect for him. I'm afraid she could be "the one" for him, and where does that leave me? Is he happier with her than he was when he was with me? Why does this have to happen to me? Why did I let him in my life?
I remember at the very beginning of my sophomore year, he had ended it with me for the quarter. I couldn't let him go, so I 9(we) started to talk again and the rest has fallen the way I had wanted it to; except for us breaking up in April of my junior year. Maybe I should have let him go when we broke up that very first time, but I didn't. This sort of feels like deja vu. Maybe I should learn to let go this time around? But I can't. I know that I'm handling this differently than I did the first time. I just don't know anymore. I'm so confused and hurt.
My day time hours are kept busy with back-to-back/hour-to-hour schedule of classes, internships, workouts, and etc. that I don't have much time to do anything unless it's been scheduled. But when I come back to my apartment at the end of the day, I have free time to think about "us" or the lack of "us."
Honest truth: I'm afraid I can't find someone to fill his spot. I'm afraid that I won't find someone at all. Back in high school, I was so wrapped up with all that I had going for me (dance, classes, running the school, popularity, prep for college) that I didn't get in a relationship with anyone because I didn't have the time. It was also never a priority for me because I just had fun with the attention I got from other guys. I thought it would be nice to have a boyfriend, but it was high school and I didn't want to be tied down. I didn't think I wanted/needed it. Nowadays, I have become someone I didn't think I was going to be; someone that wants to be tied down in a relationship. It's like the saying: you never know you wanted/needed it until you had it and then lost it.