spudserella,
This is a common question, so you might read some of the previous discussion threads about it:
As you'll see, when and how fast to taper is a subject of debate and a lot of variations among doctors' opinions. Tapering too soon can cause blood counts to crash, and that's the usual setback that causes doctors to increase the dose again. Tapering too slowly can subject you to the side effects of cyclosporine, both minor but annoying symptoms and potentially serious symptoms, longer than necessary.
I don't know if your icky feeling is a result of the reduction in cyclosporine, so getting your next CBC is the first order of business. If your counts are falling then you may have to get that dose back up. If your counts are stable then it might be worth staying on the lower dose, even if it's causing you to feel so poorly. If it's temporary you might put up with it "for a good cause".
It might have been safer to go from 20mg to 15mg before dropping to 10mg, but if you're basically OK at 10mg then that's a good sign. You might talk to your hematologist about going to 7.5mg or 5mg to be a little more cautious. Rather than dropping a certain
amount each time I'm surprised that doctors don't have patients drop a certain
percentage each time (subject to available dosages). But I'm not a doctor so the recommendation should come from your hematologist. I just remember that my wife felt fine during her taper, until she finally reached 0mg, when she felt just awful. We wished that she'd tapered those last milligrams even more slowly, or at least that she'd had more warning of what was likely to happen when she reached zero.
By the way, I'm really glad to hear that you haven't developed GVHD, even after a year. That's very good news.