Who can i talk to?

My grandad has brought me up and has been like a father to me. He is battling cancer for the third time and this time its unfortunately winning. On top of the upset of seeing him go through it, im finding it devastatingly hard as i feel like i am losing my dad and grandad at the same time! I am 26 and have never experienced death before so i have no idea how to cope with it and feel very scared! Who can i turn to and talk to to help me stay strong through this?