Lots of good advice here.
I always felt the same as you. But after awhile I realized where my weakness lay in designing quilts and where my darling SIL excelled. Now we trade ideas!! Her sense of color is better than mine but I think my sense of proportion is better than hers and we compromise (or agree to disagree!) on some layouts. Even if you feel like you are not creative there are always good ideas on google search or pinterest. Happy quilting!!