Sandy-
A proverb in music studies is that "theory follows practice."
You have obviously absorbed a great deal by reflecting on your experiences. That's how theory comes about.
The only difference is that you have formulated ideas in your mind without the "conventional" vocabulary those observations are usually expressed with.
My own experience was much the same. In my younger days (before dirt was discovered) I experimented a lot, played and sang a lot, and formulated my own thoughts about what worked together and what didn't. When they sent me to school to teach me how to be logical, I learned that a lot of what I knew was right -- but now I knew how to talk about it in the lingo of the trade. I also learned a lot of other things that dovetailed in with what I had already discovered. Expanding horizons and all that.
There were also many things I thought I knew which I was taught were "wrong" -- only to find, many years later, that under more "advanced" rules such things really did have a place.
All of which is to say, if you have the time and the interest, studying formal theory absolutely will NOT hurt your spontaneity and creativity, as long as you remember the dictum that practice trumps theory.
Cheers
-Glenn