First off, a starter is not only unnecessary with dry yeast, but can be detrimental. Dru yeast should be re-hydrated as per manufacturer's instructions.
Second, 60 F is not a bad temperature for US-05. Fermented at that temperature will take longer, but produce a much cleaner beer in general. I do recommend raising the temperature to 65 - 68 degrees for a week or so after active fermentation is complete to allow the yeast to clean up any off flavors.
My guess is that your stalled fermentation is either due to under pitching because the starter didn't increase your cell count and caused the yeast to use up most of its energy reserves or that the temperature was either lower than you thought or you racked off of the yeast too soon. At that temperature fermentation may have slowed enough that you thought it was complete. A gravity reading prior to racking would have been useful.
I don't think this brew will be ready to drink for the party. If the fermentation doesn't restart after warming up to 65 or so, I wouldn't repitch your slurry, as it's is probably stressed. If you have noticeable signs that fermentation restarted go ahead and repitch it.