I'm obsessed with death and also afraid to sleep. Are these two things linked?

You are not stupid. There are many types of sleep disorders. You should seek out a professional in the field of sleep disorders. If you feel that you can't talk to your parents about what's been troubling you then talk to your school councelor or a relative.A lack of sleep does cause many problems and your interrest in death may be one of them. Please seek help and good luck to you.