I am going through the same thing. I think most of the country has been sick in the last month. My estimate is time off == time on. If you were sick for about 1.5 weeks you should be back to normal in about 2 weeks. Just stay properly hydrated and get plenty of food.
Muscle memory my man, plus the lingering effects of being sick...pop some Vit-C and a B-Complex, drink lots of water and Gatorade and next time you do this workout all will be well.