Well with toxic coma music rules exist as well, I have to keep things uniform even in the abstract.
I play guitar all the time, I play keyboards all the time, I learn to play songs i like all the time. So when I go to write, my instincts and playing are where they need to be. I think most people struggle because they lack musical talent and discipline. Most people don't put in the work. The work of knowing how to play an instrument. With out that you cannot possibly make an instrument sing your feelings. This is one of the things I take pride in. Being able to play weird chords, knowing what sounds good when you play, know how to do dark and spooky chords and progressions.
Watch old movies, the sound tracks were so good at bringing mystery and tension to the screen, this is another place I learned how to do these things.
Also, i have to play different instruments, each instrument can make me feel a certain way as well. So making them all work together is very hard. This takes discipline.
Practice, Practice, Practice.
THIS IS CRUCIAL!