Doushitemo Furetakunai by Yoneda Kou
Empty Heart by Minase Masara
Koi to wa Yobenai by Eda Yuuri
Warui Yume by Tateno Makoto
Ones where there's no formal break up but they lost touch for a bit:
Lover's Position by Minase Masara
Blind Love Kanbe Akira
Hatsukoi no Atosaki by Shoko Hidaka
Aiso Tsukashi by Saki Aida
I'm sure there are tons more but those are just some of my favorites bc I really like yaoi break-up scenes too lol as long as they get back together! Hope this helps.
Manga about the couple breaking up (like something emotional) but then ended up back together again. BTW I've already read Life Senjou no Bokura
It could be yaoi, shoujo or anything good