Get yourself a bottle of B-12, take it, and before you know it, you'll be over that slump. I was going through the same thing earlier this year and was telling my sister about my "blues" and she told me to get some vitamin B-12 and start taking it. I did. And it worked. I am back to my old self; and after a Dr's appointment in which I have to list all my medications, he didn't say a word about the B-12 I added (not his idea); but asked me how I am feeling and when I said "fine" he still didn't mention the B-12 (continue or discontinue) at all. So I am still taking it.
Back to this original subject: Purge or don't. My secret that works for me is to periodically give quilting lessons, and allow the students to go through my stash and patterns, and pick out what they want to make and use; let them use whichever one of my machines they want to. Gets rid of a lot of fabric, and occasionally a sewing machine (for sale); I love all my machines, so they are pretty safe from the "purging" efforts. As far as missing the fabric, that doesn't happen.....