does someone know this movie?

Hey guys I'd like to find the name of this movie, so it's a girl
she has cancer she should be around 17 or so, maybe less, I remember
that she goes to a school dance with her boyfriend that also has
cancer… they meet at the hospital.. I also remember that the
girl's mom cuts off her hair to support her daughter . at the end
the girl dies.. is not a walk to remember . so thanks hope someone
knows..