I love you to the moon and back

Hazel, a "normal" 17 year old teenage, went to go visit her boyfriend for the weekend, but instead she found out he was cheating on her.
Hazel was born with Acute lymphoblastic leukemia (ALL, aka a type of cancer) and it went away by the time she was 12, but she still had bad symptoms.
Finally, she was going to be able to go back to school. But she wasn't gonna tell anyone.
But that's when she decided she was gonna move in with her boyfriend. Now she was left alone.
But little did she know that some people would change her life.
But who would those people be?