Seeing My Grandpa After His Passing

I'm not going to write a novel because I don't have the patients to type anything lengthy, but I'll briefly explain what I have experienced. When my grandpa was on his death bed when I was just a little kid, he would say he saw stuff and he kept on telling my family to lock up their valuables, obviously he didn't trust them, he seemed a little scared too, so I was told. Anyhow, I was really close to him, and it's strange how I started to see these things later on after he passed away, and the first thing I saw was him. I was looking through his office he use to work in, and when I started to walk out the door I noticed him just standing there, he was smiling at me, I wasn't too sure what to do, but I couldn't help but to smile back. I eventually had more experiences like these, but with random "people" whom I did not know who they were, but I did have some experiences like I saw some white figures around me. My first thought was angels, I honestly thought that they were first angels, however I do not know if that's what they were or not. Later on down the road everything just started to vanish which saddens me a lot. I think that the last thing I saw was a pair of glowing red eyes looking at me while I was in bed one night, and that frightened me. I often times would here some whispers as if they were right next to my ears saying my name. I often and still can guess something will happen and it will happen. Why can't I see anything anymore, why can I predict stuff? I need help.