I’m sorry to say you probably do need an intervention. I don’t think you have ever said exactly how much yarn you have (or fabric for that matter), but I imagine this huge stash that you could never use in your lifetime. That’s too much. However, it’s your money and if it makes you happy, whose business is it?
For me, storage space and budget are big concerns, so I buy yarn as I need it for projects I want to make. I’m not an avid knitter, but I have done lots of scarves, hats, dishcloths, a couple of baby blankets, a large afghan, a baby sweater and one sweater for myself, which I didn’t like once I got it finished.
I keep a small stash of quilting and other fabrics and hang on to scraps so I always have fabric to work with when I feel like making something, usually bags, wallets, coasters, doll quilts, etc., but if there is something larger I want to make like a quilt, I buy fabric for that project. I just bought my first quilt kit for a baby quilt for the grandchild we’re expecting in January, so I’ll see how that works out. It was on sale for half off, so it didn’t cost a lot.
If I had the money, and the storage space, I would probably buy fabric for a larger stash, but I don’t think I would buy yarn. It’s too expensive, and I just can’t justify spending money on something now that I might use far in the future, or not at all.