My mind won’t let me believe my dad is dead.

So , my dad died almost 4 months ago of a pancreatic cancer and I always get this weird feeling that he isn't really dead, like he's still with me and I don't know why but this feeling scares me. I'm only 15 , 14 at the time he died and I think it might be something to do with how young I am to have a parent die or something. He was never around when I was little , left my mom when I was 3. I keep having dreams where I see him in my dreams and people don't believe me that I've seen him because obviously he's dead . Not sure what to do.