Writing romance (without sounding like a sap) doesn’t have to be an exercise in clichés. Learn to avoid this genre’s tired tropes, or at least how to use them to your advantage.
Black and white is great for photography. In stories? Not so much. Painting your fictional characters in shades of grey is crucial.
There is no right way to create and use character backstories, but with practice and revisions, you can find the happy medium between too much and not enough.