Music Theory vs. Your Ear
The mass of rules, possibilities and concepts in music theory can be overwhelming or even intimidating for your own writing. However don’t give music theory a higher value than being a tool. Changing your music for the reason that it is theoretically not correct even though you actually like it is probably the worst thing you can do.
The important thing to understand with music theory is that many concepts are overlapping and there are many viewpoints on the same thing, sometimes with the effect that some concepts might even partially contradict each other depending on how you look at it. Music is an art form and not a science, which makes rules flexible or even changing completely over time. If you try to approach music from the scientific standpoint only, things will quickly become very frustrating.
Music theory can be helpful in certain situations to get you through moments when you’re stuck or things seem a little strange but it can not be stressed too often: your ear and your intuition should always have the highest priority. If it sounds good, it is good. Period.