HALP

I believe this one fits what you're looking for:
http://www.mangago.me/read-manga/lonely_to_organdy/

http://www.mangago.me/read-manga/j_no_subete/
http://www.mangago.me/read-manga/boys_next_door/ (kind of a bittersweet ending)
http://www.mangago.me/read-manga/zankoku_na_kami_ga_shihai_suru/ (again, a bit bittersweet)
http://www.mangago.me/read-manga/yoru_to_asa_no_uta/
http://www.mangago.me/read-manga/under_grand_hotel/
http://www.mangago.me/read-manga/aoi_haru_kai_ito/
(not tragedy, but really romeo&juliet-esque until the ending)

i don't really think that good ending, i cried like a baby xD

http://www.mangago.me/read-manga/hybrid_child/ not perfect ending, where everyone are happy, but it's not too sad
http://www.mangago.me/read-manga/endless_world/
http://www.mangago.me/read-manga/mahoroba_no_hibi/
http://www.mangago.me/read-manga/500_nen_no_itonami/
http://www.mangago.me/read-manga/mods/
http://www.mangago.me/read-manga/back_in_time_to_you/ maybe?? idk how it ends
http://www.mangago.me/read-manga/hebi_no_seikatsu/ first couple
http://www.mangago.me/read-manga/senya_ichiya_shitone_no_himegoto/ tragedy in the past

I've read lonely to organdy sometime ago, and trust me, I'm such a baby, I cried ;A;

will try and read them all! thank you very much (●'◡'●)ﾉ

Thank you very much! ヾ(❀╹◡╹)ﾉ~ I'll try my best not to cry since I'm such a baby

No problem, hope you like them ^^

Oh also, forgot this one! http://www.mangago.me/read-manga/red_theatre/

I don't think ur crazy :) There's a lot of people who read tragedy for the same reasons. The catharsis thing seems to be effective, even though I don't really get how it works.
http://www.mangago.me/read-manga/rasen_no_kioku/
http://www.mangago.me/read-manga/the_specific_heat_capacity_of_love/
http://www.mangago.me/read-manga/kosha_ura_no_natsu/
http://www.mangago.me/read-manga/watashitachi_no_shiawase_na_jikan/
Happy endings will be left to your interpretation (=・ω・=)

I appreciate your help. Thank you for these recommendations and also for thinking I'm not crazy (▰˘◡˘▰) thank you very much