Your quilt looks wonderful =) I'm making an art quilt right now (my first) as part of a challenge project for a quilt show so I know how you feel. In the very beginning I didn't even want to cut the fabric for fear it wasn't the right color or shape. As I've continued working on it I kinda like it now, even with my "mistakes". I've decided the "mistakes" give it interest and character!! I'm almost done and it looks nothing like I had imagined originally but it's more about process and the more I made changes (some just stumbled upon) it was for the better.
I like your interpretation - keep going and if you aren't sure about an area come back to it later and audition different fabrics. It's going to turn out great.