Is it okay for me to feel like this?

So my birthday is tomorrow and i'm going to be spending it alone. At my house. I can't do anything fun like invite my friends over because i'm sick. My dad has to work, my brother is going to stay with our cousins, and my mom has to take my Granny Carolyn to a doctors appointment. So i'll be spending my birthday all by myself while i'm sick. I don't know if I should cry or get mad. Is it okay for me to be mad at everybody for abandoning me on my birthday? Is it okay for me to want to cry?