I also made a spare room my sewing space, and when I moved my sewing stuff there that was the last time I purged. I do every now and then get rid of some items. A few months ago our guild had an activity where you could auction any of your items and I had a tote full of quilting gadgets, patterns, rulers, panels etc. I have tried the system of going through your fabrics and have a pile to throw, donate and keep. I end up keeping everything.
I just started to have a sewing/quilting class on Tuesdays evening in our church and decided that I will use my stash to start these ladies in this hobby..some may become addicted like I did..