I've rated them from least to greatest, in terms of how obsessive they are over their MCs:
https://www.mangago.zone/read-manga/black_or_white/ (Established relationship, both actors.)
https://www.mangago.zone/read-manga/derail/ (Both are infatuated with each other, and it's kinda twisted.)
https://www.mangago.zone/read-manga/o_g_oh_my_god/ (This is lower on the scale because of its lighthearted tone, but the ML does kill for the MC, so...)
https://www.mangago.zone/read-manga/why_are_you_so_kind_to_everyone_except_me/ (Some stalking and manipulation, but nothing crazy.)
https://www.mangago.zone/read-manga/geu_kkeute_issneun_geos/ (Obsession with the MC that turns into infatuation and love.)
https://www.mangago.zone/read-manga/a_proxy_painter/ (I'm actually not sure if this exactly fits your profile, but I'll put it here anyways. ML is an asshole towards the MCs feelings, but there's a good redemptionarc, so...)
https://www.mangago.zone/read-manga/black_mirror/ (Perfectly fits your profile, not triggering enough to be traumatizing, but it's definitely not normal.)
https://www.mangago.zone/read-manga/the_foul/ (He is OBSESSED.)
https://www.mangago.zone/read-manga/palace_of_bardo/ (This is very triggering, I don't think it's enough to be TRAUMATIZED, but it's very angsty and deep. I personally love this one, I've read it twice. But I will say this, it's not for everyone.)
Anyone got good recommendations on bl’s with crazy obsessive tops? (nothing trauma inducing like nonzerosum though ╥﹏╥)