Sad yaoi

For me, these are the mangas that made me cry:
1. http://www.mangago.zone/read-manga/hana_no_miyako_de/
2. http://www.mangago.zone/read-manga/sakura_gari/
3. http://www.mangago.zone/read-manga/yozora_no_sumikko_de/
4. http://www.mangago.zone/read-manga/new_york_new_york/
5. http://www.mangago.zone/read-manga/hatsukoi_wa_gunjou_ni_tokeru/
6. http://www.mangago.zone/read-manga/tadayoedo_shizumazu_saredo_naki_mo_sezu/
7. http://www.mangago.zone/read-manga/hybrid_child/

All are completed, also I think no.4 is a shounen ai

http://www.mangago.zone/read-manga/nanadome_no_gomenne/
http://www.mangago.zone/read-manga/eien_no_aida_ni_miru_yume/
http://www.mangago.zone/read-manga/love_letter_sakai_kunie/
http://www.mangago.zone/read-manga/kimi_no_kanaderu_hikari/
http://www.mangago.zone/read-manga/ashita_shinu/
http://www.mangago.zone/read-manga/hana_no_miyako_de/
http://www.mangago.zone/read-manga/mahoroba_no_hibi/
http://www.mangago.zone/read-manga/machina_angelus/
http://www.mangago.zone/read-manga/birthday/

This one is ongoing, but there's truckloads of angst and good plot: http://www.mangago.zone/read-manga/tourou_no_ori/
Completed:
http://www.mangago.zone/read-manga/sabita_yoru_demo_koi_wa_sasayaku/
http://www.mangago.zone/read-manga/mahoroba_no_hibi/
http://www.mangago.zone/read-manga/yuki_iro_machiboke/
http://www.mangago.zone/read-manga/hatsukoi_wa_gunjou_ni_tokeru/