Overcooking pork can lead to dryness. It can happen to experienced and novice cooks, so don't feel bad. While it won't be as juicy as perfectly cooked pork, you can still salvage an overcooked roast. Let the meat rest and cool a bit. Then slice it very thinly AGAINST the grain. Bring 2 cups of broth or braising liquid to a boil in a pan or skillet. Add the pork slices and reduce the heat to a simmer. Cover the pan and allow the pork to cook for a few minutes until it is moistened. You can serve at this point, but allowing the meat to cool a bit lets the pork firm up and hold more moisture. Alternatively, you can shred the pork. Toss the pulled pork in warm broth or braising liquid to add moisture before serving. Pulled pork will absorb the liquid more easily.