Take me away:
Thank youu I'll def watch it :)
Yes the ML and FL's parts are the only ones worth watching. He is so obsessive!
Another one is Love in Sadness, both male leads in this are obsessive in their own way.
You can also try The Last Empress , I am not sure whether it's 100% what you are looking for, because they focus more on revenge than romance, but it has a very unhealthy dynamic, especially when it comes to one of the male leads. Beware part of the summary is a bit deceiving, I would even say not true.