What a great way to start the new school year... a new look! I would suggest going for a medium short style. Something that is off the shoulder but below the chin as to not add to you naturally round face shape. Angling your bangs a little more and making them more full will help in achieving more style in your entire look. I would go for lots of choppy layers to help crave more movement and style so that you don't have the same old look only shorter. Choppy layers will really create a fun and flirty look that I think would be perfect for your new school year while helping to soften and camouflage the roundness in your face!

The ladies gave you some great advice! I definitely agree with the Kristin Cavallari look on you. Angled bangs would be great!

These would look gorgeous on you :)

You'd look great with these.
(Morena Baccarin, Gennifer Goddwin, Michelle Williams)

Here are some ideas:

This would look great!

Personally I think you should go for a pixie cut, I think you'll look very pretty and it's something you love, so go for it, I believe you will look your age and you'll feel and look like a new person. Good luck :) xoxo