A good excuse to get out of a sorority ?

[Krumpits&Tea☺]

I have been debating this this whole summer. I have decided to graduate early this december, and the only thing standing in they way is the sorority I am in. I have two positions, and I do not want to be in it anymore. The constitution says I have until the second general meeting to take an inactive semester. I want to be just run away from all of it, but I want to come up with a good excuse with leaving ( obviously for me right now it just does not make me happy and I want to focus on school) but I feel that they will be like "Oh thats not a good enough excuse" but its my life and I don't want to be a part of it now especially with graduation coming up in three months and I need to figure out what to do with my life and study for my mcat in january....