Your wort is fine. Some people mash overnight due to time constraints. Your beer, on the other hand, is more likely to suffer due to the underpitching of yeast. This is indicated by your lack of timely fermentation.
A good tool is the yeast pitch rate calculator at
www.mrmalty.com. If you want to skimp on the yeast, go with US-05. US-05 will produce great results. To me, a flask for making starters is the best $20 you can spend to improve your beer.
As for what you can do now, perhaps add another vial or 2 of yeast to bring it to the proper level. I'm not sure how much of a difference it will make at this point if the yeast has already replicated to its amount under stress. Good luck.