The following are entries from John Winchester’s journal written immediately after Mary’s death, taken from the [[Official Website]]. As well as the transcript, I’ve screencapped the pages themselves, so you can download/view them too, if you like. I’ve not made any editorial changes (any spelling/grammar mistakes are all c/o ‘John’), each entry is separated by page. In other words, I’ve changed nothing. You might get a kick out of looking at the screencaps too, though, the writing does change a little (gets more crowded in, anyway) at points.
The material here can be considered canonical - you can find the journal on the official Supernatural website.