hey buddy,
I have a regal too that got ich within the first few days that I got him. It spread to the yellow tang that I got with him too. I had a flame angel that died a few days ago and he was just in BAAAAD shape with the ich. ever since I took out the flame angel that had the worst and I was feeding like crazy too, the regal is better now and the yellow tang is pretty much free of it too. I don't know much since I am really new to the hobby too, but I was feeding brine shrimp to them and soaking it in vitamins and they were eating it like crazy. I was feeding like 3 times a day. Finally they're eating well. I also got a cleaner wrasse when I got the two tangs and they have been a lot more comfy letting him pick at their parasites. Luckily they're in much better shape. I was really afraid. I think the key is to keep them eating and like the other guy said, keep your hands out of the tank and keep things as serene as possible for them. I didn't cut back on the lights but I think that will probably help them relax too. But my guys won't feed much without the lights on. Just try to keep things as consistent as possible, temp, food, lights, water changes, etc. You should be ok. The regals are really prone to ich. but they will make it if you keep things simple and untouched.
Good luck.