Here r some...
http://www.mangago.zone/home/mangalist/815165/
oh also this one it’s not bl but still the saddest story ever
http://www.mangago.zone/read-manga/my_life_in_two_panels/
Also..
A shoulder to cry on
Rift (corno)
Jazz for two
http://www.mangago.zone/read-manga/form_of_sympathy/?GuZQ
Bl : http://www.mangago.zone/read-manga/december_rain/
And i could also give u a list of specific Avogado6's mangas that are the saddest ones but their not bl.
I really love angst, or something that tug ur heartstring and make u cry. But the prob is i think i have read all the good ones :"( is there any rec? It can be new or underrated bl. Thanks!