Instead of trying to figure out what to dispose of, why not decide what to keep?
You could pick out several patterns of quilts or projects you feel inspired to make. Go shopping in your stash for fabrics for each quilt, and then "kit" them up - either in bags or totes. Include everything needed to make the quilt or project - specialty rulers, fusibles, batting, etc.
Then let everything else go. Just another option to consider.