Help please

Can someone please help me help my child deal with the kids of his fathers he is 3 almost 4. His dad passed away 8 days ago... because of his dad's work schedule he just realized that daddy hasn't been here. He asked where he was and i told him daddy went to heaven... He cried and kept saying he wants him back here. That he misses his daddy and he didn't want him to leave. I just held him and talked with him saying that I miss daddy too and that It will be ok. I have no idea what to do for him. My heart aches for him... any tips from someone that has went through this please. ( also I am relgious so no comments about me telling him he is in heaven )