Try "Kokoro Botan" by Usami Maki. The guy isn't the classic psycho yandere, but yandere-ish. He seems very sweet but actually has a quite the twisted personality. I love all the Usami Maki mangas but this is 1 of my fav!
http://www.mangago.zone/read-manga/kokoro_botan/
http://www.mangago.zone/read-manga/high_school_lullaby/
http://www.mangago.zone/read-manga/kawaii_akuma/
2 of my fav Yandere chara manga. Although you might have read them already. You should check out skuracry's yandere list. I think there are quite a lot of them there.
can someone please recommend me some shoujo manga with male yandere ?