(I enjoyed this one, but it is really gory, and if you are sensitive to that stuff then I don't recommend it)
http://www.mangago.me/read-manga/pumpkin_night/
http://www.mangago.me/read-manga/kamisama_no_iutoori_ii/
http://www.mangago.me/read-manga/monkey_peak/
http://www.mangago.me/read-manga/shokuryou_jinrui/
http://www.mangago.me/read-manga/zanuff_the_butcher/
http://www.mangago.me/read-manga/when_night_falls/
http://www.mangago.me/read-manga/apocalypse_no_toride/
http://www.mangago.me/read-manga/brutal_satsujin_kansatsukan_no_kokuhaku/
http://www.mangago.me/read-manga/gofun_go_no_sekai/
http://www.mangago.me/read-manga/real_account_ii/
Brutal Satsujin
sorry off topic but i love everything u reccomended here omg
they're very good manga haha
ive read everything u recommended here and they were so good especially the when night falls ヾ(☆▽☆)
If you're ok with webtoons you can read them on their website it's free
these ones have jumpscares
Chiller
Shriek
Horang's Nightmare
Gremory land
Melvina therapy
Dead days
The Cliff
Not sure if horror but they're really good
Friday Forbidden tales
Pigpen
Bastard
Horror manga's?