Today I bought Chloe the Thundershirt, it's supposed to help with anixety in dogs. It works something like a weighted vest does for kids with autism. My son has autism and a weighted vest did help him calm down and focus, so it's worth a try. Check it out:
www.thundershirt.com
I hope it helps, cause I'm at my witts end! We are gradually adding a new food, we chose Nutro Ultra for small breeds. Maybe the combination of the two, plus the Prozac she's already on will help.