Your pork meatballs could be dry for a couple of different reasons. You overworked the meat. To ensure this isn't a problem, use your hands to mix the ground pork mixture until just combined instead of rigorously squishing it and folding it to combine the ingredients. Yes you want the ingredients to be thoroughly combined. However, overworking it results in dense, tough and dry meatballs. Another reason you could have ended up with dry pork meatballs is that you overcooked them. To avoid this, simply keep a close eye on them as they cook up in the skillet. They don't take much time at all and you'll need to constantly flip/rotate them throughout in order to ensure even cooking and prevent burning. PRO TIP: Remove the skillet from the heat a minute or so before you think the meatballs are done. The residual heat from the skillet will finish cooking them.