i'm not here to tell you any of the things you mentioned, i'm just really curious why do u hate the ending that much. for me it actually made sense a lot, so i would really like to know what is your opinion based on. really, it's just curiosity, so please don't be offended
The main characters change of mind was way too sudden. I didn't really notice him enjoying his time with his ex. I didn't really notice any Stockholm syndrome going on for him. The ending is extremely rushed and the guys way to solve the problem was absolutely ridiculous. I can see him thinking that the main character was broken beyond repair and decide to kill him. But again, it was all sudden and unexpected (unexpected usually means something good. But here it gave me the feeling that author just wanted things to be unconventional and forcefully made the good guy bad). If he decided to actually pull it off "kill yourself or I'll kill him" that means he's got mental problems too. And that's way too many characters to be mental in one manga.
Even earlier, their actions weren't exactly explained. If the main character decided to spend so much time with the good guy and not contact the ex i expected that he really wants to leave him. But he wants to come back for basicly no reason. The thing here is that if someone wants the character to be bothered by something, it's good idea to show it. But there was nothing of the sort. (If there was,i didn't notice.)
I can't see why he didn't just run away or went to the police. (Sorry, it is a while since i read it, maybe it was explained).
To sum it all up i don't like the fact he was still in love with his ex. I feel like i didn't get enough explanation for that and it was just sudden change of mind. The whole"we got 3 chapters left guyz gotta solve this quickly" made it feel like someone was trying to kick you out of the restaurant because they're closing in few minutes. There are few more things i don't like but i am not sure how to explain it. (English not native language) + i feel like they are the things that are different for everyone and me telling how it is for me is useless.
Thanks for making sure your comment wasn't "attacking". Sorry if i didn't put my thoughts into words properly. If you really want to know more we can try private conversation.
The ending sucks. I am so fucking disappointed. But i expected certain things and i didn't get them so it's very personal... Well, mental struggles and all that stuff is easy to fuck up. And it's no different here. The ending just popped like "ugh, it's getting nice, time for sudden change of mind and making good guy crazy too". The epilogue is absurd. I enjoyed this comic really long and liked the story but i was almost at the end and nothing was resolving so i expected some weird shit at the end but what i got was just bullshit. It was such a good comic. And then it all went to trash. Eh... I guesa i will just enjoy remembering the good part of it and ignore the fact it ended in such crappy way.
For anyone who read this comment:
I don't need you telling me "it was good!" "you're just stupid/immature/simple-minded!" bc this is my opinion and i won't change it now, this comic really ended stupidly for me. If you liked it, then good for you, I'm glad you got to enjoy yourselfes. But i didn't. And you telling me I'm wrong won't change that.
Summing up, it was good but even the best can be ruined in the end.