Broke up with my girlfriend. Feeling horrible now?

We've been together for a year and a half. Happy and great for a year. Not so for the past 6 months. Reason being i've became much busier and have no time for her. So basically, i've neglected her for the past 6 months. She's been real patient with me and treats me nice even though.

I know i'll be busier in time to come, so i had a talk with her today and i broke up with her, considering the fact that i would be selfish to ask her to stick to me. I cried, cause its like i only realize how much i'll miss her and how much i love her after we broke up and i was leaving.

And you know what? She understood that i have priorities like school and life goals, and she replied " Don't be sorry, if i had life goals, i would have probably done the same."

I'm so upset now...