From the title of your thread, I thought it was "talk like a pirate week," but no, it's about a very very frustrating experience! So sorry to hear that your hat went the wrong direction! Yeah, acrylic just doesn't shrink like wool does. Of course, if you'd done that to wool, your hat might fit Barbie, but it wouldn't fit any person alive! Bright side (if there is one): Maybe you can at least reuse the yarn.
Sigh! That's certainly a painful way to figure something out. I feel for you.