I'm following this thread. All of the things you mentioned are also what I am totally into.
I would personally agree with:
Because it't My First Life (this one I highly recommend)
Moon Lovers
Hwayugi (kind of; not much of a love triangle)
Now, technically speaking Falling For Innocence has a tag melodrama, but I have a feeling that you would really like it. More adult content, pretty cool love triangle (just go past the first 3 episodes that are kind of tough), possessive, but caring ML and even though there is no cohabitation, there is a lot of tension. Tons of jealousy and a jerk who quickly turns into one of the coolest male leads I've seen
Also, did you see Kill Me, Heal Me?