First, I should let you know I never watched Go Back Couple. But I watched 2 out of the 3 dramas you mentioned afterwards.
So, comparing our lists and looking at your PTW list, I would recommend:
1. From your PTW list: Another Miss Oh, Oh my Ghostess and Love in the Moonlight. Those three have sweet romance. The most melodramatic for me is Another Miss Oh.
2. From my list:
- Something about 1 Percent (2016)
- Queen In Hyun's Man - I saw that you watched Rooftop Prince. Similar premise, but I think this one is better. I think you'll like it.
- Personal Taste - not sure if you will like it. It was one of my first kdramas and I loved it xD
- Jugglers - very very sweet romance
- School 2017 - innocent high school romance
- Fight for my way
Hope you enjoy it ^^