Another yaoi I would recommend to give you the bittersweet feeling of this would be Smells Like Green Spirit. It's probably the first yaoi that I read that made me cry.
Everytime I think about Karino I want to cry. I'm sure he loves his daughter and all but he put his mother's happiness over his own. Poor guy. Oh, I'm crying (/TДT)/
Another yaoi I would recommend to give you the bittersweet feeling of this would be Smells Like Green Spirit. It's probably the first yaoi that I read that made me cry.
http://www.mangago.zone/read-manga/smells_like_green_spirit/