Last night Dan slept over, it was the first night I really slept in a while, and I woke up in the night talking to him I said
"Can you hear me?"
So in my head I said 'but he was dead, how can he hear me? maybe he came back' and I scrambled to turn the light on then I realized it was Dan and I said I thought you were him. And I went back to sleep.
The only thing I can do to really reassure myself that he's gone is picture him how he was in that hospital bed when they said that was it.