Okay, so the '365 Days' thing is a pretty specific vibe, right? That super heightened, almost ridiculous level of dramatic obsession, fancy locations, and questionable morality wrapped in a glossy package. If that's the mood, you're looking for the 'trashy but I can't look away' section of streaming.
'After' is the obvious one—college setting instead of mafia, but same possessive energy and dramatic arguments. 'The Kissing Booth' has some of that push-pull tension, but it's way more tame, almost YA-feeling compared to the outright steam of '365 Days'. 'Fifty Shades' is the grandma of this genre, but it feels slower, more about the negotiation of power than the constant life-or-death stakes.
Honestly, you might have better luck with some TV series. 'You' on Netflix has the obsessive love and suspense, but from the stalker's perspective—way darker and smarter, but hits some of the same 'will they/won't they but also should they' notes. The ending of '365 Days' left me annoyed, so I went looking for something with a bit more bite.
I stumbled on a Polish film called 'The Hater' on Netflix—not a romance in the traditional sense, more of a psychological thriller about manipulation, but it has that same uncomfortable, magnetic tension between two terrible people. It's less about fancy cars and more about social media toxicity, but the obsessive love-hate dynamic is there.