I don't have problems with overwatering because I use hyrdo, so I'm not quite sure how to fix it. My educated guess would be not to water it for a while until the soil seems, well, not so wet. lol. Your plant is young, but I think it should recover. Plus, unless you foliage feed, I don't think you should pour the water directly on the plant. Not only is this true during veg. phase, but especially flowering, because it will encourage mold. I hope your not using nutrients yet, your plant only looks to be about a week old or so.