Searching for Sherlock/John fanfic

[syrentearz.livejournal.com]

Hi all

I'm hoping I might have some luck here finding a story that I read I while back and can't seem to find anymore.
I can't remember the name of the story but I can give you some details of what I know.

I know it's based in the era like the Sherlock Holmes movies (Downey films), not the TV series and I'm pretty sure I read it on AO3. Slow build sherlock/Watson, sherlock is in love with Watson and Watson is oblivious/confused.
Watson is married/engaged to Mary and doesn't live with sherlock anymore, sherlock also moves to a different house as well (can't remember the reason).
Sherlock is on a case trying to catch a murderer and goes on finding clues that are left behind by them.
There's a chapter about an OMC character, homeless boy who gets looked after by a male prostitute and in the end there's a scene in an alleyway where the the older one dies from sickness and the other boy lives with sherlock in later chapters while helping sherlock with the case.
Another scene involves sherlock running into Watson and Mary at an opera performance.

I'm sorry if all this is confusing or vague but it's all I can remember, I would be grateful for any help on finding this story.