Why i keep dreaming about relatives who passed away?

almost everyday in two weeks that i keep dreaming about my grandmother who passed away 6 years ago. We are close with each other. i love her so much. most of the dream is about her passing away again. I keep crying until I wake up really crying. then last night I dreamt of her again passing away, my whole family were there waiting for her coffin. My mom (who is still alive) was beside me, and beside her is her sister who died last year and I heard her telling my mom to tell me to not look at my grandmother's head. I got scared and woke up.. It is really bothering me.. What should I do? I am praying for their soul. are they trying to give me a message? about what? please help.