The way I look at it, you MUST save some projects unfinished....think of it as leaving a legacy for future quilters to come across those blocks in some dusty antique store some day and fall in LOVE with them and will lovingly take them home to finish for you. ---Ask me how I know this? I have done some of them for those that came before me. I have been quilting for 30years and I have at least one or two UFOS that will be passed on that way.....
As for my unloved fabric (once you get that stash built up), time goes by and one day you look at it and go "WHAT" was I thinking???? I am stripping those pieces out and turning them into crochet and woven rugs that I will either sell or gift. DONT feel guilty or stressed, its part of your artistic growth as a creator of beautiful quilts and HAVE FUN