Aww im extremley sorry to hear this. My nan whom i was very close to passed away this August and im still greaving now. You do feel happier in due course but i'm not going to lie and say that you will feel completley better after a few days. Try to think about all the happy times and remember she wouldnt want to see you/your family upset. I know almost everyone says it but it is true, its what got me through the months.
Also another BIG help is being with friends, they really do take your mind off of things, im not sure whether youre still in school/college or not but when i got back to school it took my mind off of things ALOT. I hope that you feel better soon. And just remeber your auntie is at peace now
x