I haven't read all the responses, so this may be a repeat, but it doesn't hurt to take a vacation once in a while. This quilt may be the final straw, but if you walk away from it for a week or two, you will come back with fresh eyes. Next quilt you do, pick a simple FUN pattern like pinwheels, in brigh colors.
Of course, if you don't love it any more, then find something that you do love. Life's too short to be miserable.
Good luck!