I am so sorry your friends let you down. That can hurt tremendously especially after making yourself vulnerable and sharing with them. It was also bad timing regarding your exams. I am sure there is not much one can say to console you. The truth is that when people hurt you it says more about them than you. 

However, time is a healer and you have certainly learnt a lot about people and relationships because of this bad experience. Hopefully you will guard your feeling more in the future whilst still opening up your heart to others knowing that there are still some good people out there that will be worthy of your friendship.

In addition, hopefully sharing your story helped you to come to terms with your sadness and to also put things into perspective. Take good care of yourself.