Hi Sandlizard,
This is definitely one of the most interesting dreams I've heard! Lots of great imagery. I didn't know what a cat might mean, so I looked it up in my dream dictionary. It says a cat means "bad luck. Beware of a diabolic stranger who seeks to corrupt your world." The whirlpool is of course something that could suck you under. Since the cat turns into you, maybe the dream is telling you to watch out for yourself, don't be your own worst enemy? Don't dive into any whirpools? I don't know; I'm certainly no expert. I like cats and think of them as agile, soothing comforters. Maybe you need to bring out your cat-like characteristics and remain aloof yet agile in your day to day dealings.