Worst Week Ever

So last Sunday was my birthday, so I sorta labeled the whole week from Sunday-Saturday as my birthday week. I was so excited because I had plans with all of my friends for every single day of the week. Well I got in a fight with my best friend on my birthday, so she bailed on me and made me feel like shit about myself. Then the next day one of my friends who came in from out of town bailed on me. Then the next three days I had plans with a different friend, and he bailed on me all three days. Friday my best friend ditched me again for no apparent reason. And last night I rescheduled my plans to hang out with the same friend who ditched me three nights in a row and he bailed on me again.... I feel so insignificant to my friends. I don't let them see how it hurts me when they do shit like this, so they just keep doing it over and over and I feel like I can't be mad at them because they don't know it's hurting me. I feel like I'm the friend that everyone thinks it's okay to cancel on because to them I'm just a friend, and they have their better friends. But to me they're all my best friends, and the only friends I have. Is it wrong for me to be mad and upset with them? It makes me feel guilty, because I know I'm just the girl who doesn't really matter as much as their other friends matter.