I'm not looking for a specific manga, just recs
https://www.mangago.zone/read-manga/friend_line/ this one fits but the toxic one is an abusive relationship, still its really sweet
I've already read this one, but this is exactly the kind of thing i'm looking for!
Hmm I see but I cannot think of anything else like this one, maybe you can look through this tag~ But I'm not sure if they'll be like seme saving uke from the ongoing toxic relationship like you asked, or just some shitty ex bfs coming into the picture afterwards, still there might be some good ones maybe? https://www.mangago.zone/tag/Toxic%20ex/?page=1
maybe go through lists friend line is on /srs
a bl manga where the uke gets saved from a toxic relationship by a kind and strong seme. nothing violent or too crazy toxic, mostly loving fluff. main storyline is kind seme saving uke from mean seme