<human>: Can you succinctly summarize the text in 1-3 sentences?

Throwaway because my friends use reddit! 

I have a relatively small circle of friends (7 friends including my boyfriend). We have been friends for more than five years, and ive been friends with one girl for a couple months. In a week and a half ill be turning 18, and the day after my birthday AP exams begin. I had previously told my friends back in March that I wanted them to go on a day trip to the beach (an hour and a half away) to celebrate my birthday. This week they all said they cant go because it will take time away from studying, so I suggested going to the movies, my treat. Again, all but one girl (who's a sophomore and cant take AP Exams) said no. Even my boyfriend rejected my invite! 

I honestly feel very upset because its my 18th birthday, and I've known almost all of my friends since middle school, and they cant take 2 hours out of their day to celebrate my birthday. I understand that studying for AP's is important, but I doubt it'll take up their whole day. 

How do I convey that I'm very upset with them? I take time and plan their surprise parties and have always gone to their celebrations, but they dont reciprocate...
<bot>: my friends believe studying is more important than doing something with me, and I dont know how to tell them I'm disappointed.