Maybe for you doing other coloring styles does something similar to what turning an image upside down would do. It lets you see the flaws you've become comfortable with and can't see in a normal situation. Since your main goal in making art is to make something that looks good, you revert to the style you're comfortable with, the one you can't see the flaws in and can be happy with. If you want to make learning your new main goal and get past it you'll have to be able to let yourself make ugly art.
BTW, I really like your coloring style.