sad yuri? some that will hit me really hard pls
I don't know if you read these two but here you go:
http://www.mangago.me/read-manga/philosophia/
http://www.mangago.me/read-manga/vengeance/
Its not really sad but i shed one or two tears(besides ive never read yuri before and this is the first one ive read)
http://www.mangago.me/read-manga/yuri_wall/

yuri or yaoi w an extreme lowlife character. maybe like yatamomo?
http://www.mangago.me/read-manga/yuki_iro_machiboke/