Hello Paula and welcome.
I'm so sorry such a sad loss has brought you here looking for some comforting words to maybe help ease your pain.
You must have been very close to him, and I'm sure he knew this and loved you back very much.
It's very early days for you right now, so everything is very vivid still in your memory of him, and this is what can spark you off at the least little thing remembering maybe one of those happy times you laughed and spent together.
Having run this site for over 20 years now Paula, I can only promise you that your pain will ease, and the days become much more bearable than they are now.
May i suggest you use this thread to open your heart out to unload all those hurty bits that can disturb your mind from a restful sleep. No one here ever judges one another, only listen silently with a sympathetic ear. Writing all those things down really does help I know for a fact.
So may I wish you great strength and courage in the days ahead Paula, and that your beloved grandad sends you his peace of spirit to help heal your broken heart.
Take care Dave.