commakaze answered:
I REMEMBER THAT FIC. Also, FOUND IT! http://sherlockbbc-fic.livejournal.com/12826.html?thread=66321178#t66321178
WE HAVE A WINNER! Thank you, commakaze! This is the fic I was talking about earlier.
In which Sherlock investigates a murder using the vlog entries of the victim. That victim’s name is John Watson, and Sherlock finds himself falling in love with the dead man, entry by entry. It was lovely and sad, and is certainly worth a read!
ETA:
it can also be found here at author’s LJ: http://diminua.livejournal.com/tag/vlogger%20john (just ignore the first post about torchwood)
Thanks so much, guys! I really appreciate it.