OMG! Im so sorry I didnt see this update sooner! Just remember..he isnt suffering anymore and he is in a better place, with your grandmother. I dont know if this will help or not but my grandmother has lung cancer and is going to pass very soon. She told me not to be sad, that she will always be in my heart. She also said that whenever I see the trees blowing in the wind...thats her saying hello.
Everything will be ok. He's in a good place. My prayers to you and your family.