Emptyness

So today I spent the day with my two best friends. We went to the movies and saw She's Out of My League, which was way better than I expected. Overall it was a fun day that any normal girl would have been perfectly fine with. However I am not that normal. As soon as I get into the car instead of thanking my mom for driving me and funding the day I lash out like no other. Once I get home I feel very empty. I am not quite sure how to fix this. I know I am not depressed or anything and I am still upset over last weekends fail. I'll keep trying.