Stupid me for thinking that this author can make good endings just cuz the only other manga had a good ending (and I'm not talking about happy endings but rather well-written and logical endings!).
Anyway, this manga can still be saved if gomi wakes up after having that long talk with Kuroko and figures out that that whole garden scene was a nightmare and then he looks for Kuroko and finds her dead, somewhere like in the washroom or wherever. Because yes Kuroko was happy but she didn't confirm that her suicidal mindset is absolutely gone. So, maybe she finally gathered up the courage to end it once and for all. Also, remember how cops are looking for her and the fact that already so many people have already seen her face?? Maybe, the cops finally figured out her address and maybe, somehow Kuroko noticed that, panicked and she finally killed herself? Did you notice the look she gave before she fell asleep? That look felt a bit weird to me, like as if she was still depressed or maybe it was just a feverish look, IDK.
Now, if it's not a dream then this is incredibly a bad writing. Not only do you tell me that he, who looks like a toothpick, somehow magically fuckin survived but now he's healed enough to look for them, found them in such a secluded place where nobody else was, hid like a pro ninja and slashed her before anyone (gomi) could even see his ass??? It makes 0 sense and sounds like an outlandish,rushed, nonsensical ending and this ending seems worse than his/her's previous manga ending. I would say that this story started to go downhill as soon as we learnt that somehow that crazy scrawny husband survived,and then how all her money got stolen, at a very conventional time (I mean.... Do you think that the husband hired yet another guy to rob her?? At this point that sounds more believable than the ending of this chapter)