I know your pain. I felt the same way about a Carpenter's Star that I made so I took the WHOLE pieced top apart & changed one fabric that just didn't work for me. It was a ton of work BUT I was so much happier with the change.
Your quilt top looks just fine the way it is but I also like the other fabric too. What you have to decide is "is the change worth all that work" ? It might be easier to make an entirely new top. Let us know what you decide. If you have one of those electric or battery powered stitch rippers you would have it apart in a few minutes. I have one & it is awesome & would not be without one. Good luck.