If you haven't been a misadjusted loon at some point in your life, this isn't for you. If someone told me this is a CIA operation to mark potential future terrorists I'd almost believe it.
The protagonist is effectively a very extreme caricature of a teenage loner, getting pointlessly worked up in his own head, and then committing unsavory acts toward others (not described here, because they are kind of disturbing), starting with some misguided "justice" toward bullies, culminating in
taking revenge on the girl he loves, for the "sin" of loving someone else (he "needs" it to get over her, as if there was anything to get over to begin with).
Then he finally realizes he has been a jerk (pun intended),
confesses his acts, and after going through bullying, redemption
(he is almost a normal person now)! Is the arc somewhat believable? Yes. Is it a masterpiece? No. Being believable is the baseline for telling a story, it's not something to be applauded. It's also still very convenient for the protagonist that some people are willing to extend a hand somewhat early on after the "pivotal point", and the girl he ends up with makes no sense whatsoever, from a narrative perspective (unless you think people who are atoning in their own ways make for excellent pairings, no matter what the previous circumstances between them are).
So, the plot is not particularly original (once you ignore how extreme it is in certain elements), the protagonist goes from unlikable and insane to regular (nice) guy, which isn't exactly compelling. The other characters aren't one dimensional, but they don't have much depth either (the series is short and there is a lot of wasted time, so it would be hard to do much with them anyway).
At its core, it's just an unremarkable coming of age story, which meanders quite a bit before getting to the point, and doesn't give enough screentime to most of the supporting cast. Plus, you have to wade through some disgusting content early on to get there. I genuinely believe this would have been better with 90% less teen angst in it. It's a story that has been told before and better, and will likely be eclipsed in the future as well.