Try the sparkly again with a good base coat. The glitter will be on the base coat instaed of directly on the nail and won't be as tough to remove. Also, if you use more than one coat of polish, apply the first coat without shaking the bottle first.
This won't work with all sparkly polish, but I have had some where the glitter all settles to the bottom - that's the one I'm talking about.
Use an emery board to rub it off, Laura. I learned the hard way to always use a base coat under sparkly polish. I did find that the emery board worked pretty well to get it off and didn't take the nail with it. Make sure it's the cardboard kind, the metal diamond dust ones are a bit too rough.