I finally overcame my fear sufficient at least to divide the skeins of yarn into smaller skeins preparatory to dyeing them. It took a few turns, but I got the hang of the niddy noddy, which you wind yarn around to reskein. I googled it and got a couple useful links - this one and this one with a video - and got under way.
After winding about 100 turns around the thing, I realized that counting the number of turns was the LEAST efficient method of telling how much yarn was on it. I realized I should have weighed the original skein, then go by weight to tell when I had wound enough on there. So I began to unwind from the niddy noddy back onto the swift, but soon got the yarn all tangled up. I worked at the tangle carefully for about half an hour, until I finally got so fracking frustrated that I stomped my foot on the floor a couple of times. Adam came up and tried to calm me down, but ultimately I threw the tangled yarn out the window.
Eventually, after taking a break, I came back to it and was able to get both skeins rewound and divided into smaller sections. I even went out, got the yarn off the bushes and brought it in and completely untangled it. I weighed the large skein, divided it by four, added the weight of the bare niddy noddy, and used that as the target weight of the niddy noddy with yarn wound on it. The silk is yucky yarn - very toothy and unlovely. I think I have twice as much of the wool than I thought I bought, but I am not sure. Ultimately the only way to tell would be to count the turns, but I don't think I have the patience for that.
Learning is really hard. Really trying to the patience, and frustrating, and ego-bruising. I hate it.