From what I remember rn, I'd say (in order of most recommended):
Yukue Fumei - depressed and codependent, but mostly because of the... most recent conflict in their lives. Yikes.
Mayonaka no Ore wo Mite - freaky and unhinged, but they do know when to keep it professional so the freak4freak is partly a sidedish to the plot
KasuRich - they're both so codependent they start doing a whole 180° to turn healthy again (not really, tho, they're still freaks). Sometimes it's so over-the-top it get comedic
ZERO LOVER - mostly the horny kind of freaky, but they're also both not quite right in the head
Loving Too Much Is Just Right - clingy x clingy, but tbh they could be freakier. Mostly just possessive
Kabukichou Bad Trip - purely the horny type of freaky, they're actually really healthy in the head, just a bit of a possessive streak
EAT (by nagabe) - this one is pretty up there on the freak4freak scale but, it's furry. Do with that what you will

No other toxic/obsessive/freak4freak BL manga will ever top this one, I fear. We peaked here, folks.
I know the author is working on a different series already but I'll never stop praying they may one day go back and give us like, one more doujin for this series at least... please...