Press the home button and the power button and hold for five or 10 seconds and release it should go to recovery mode. You may also want to try reseating the battery to make sure it has a good connection. Abbot

It may possibly be that the connector to the digitizer was loosened by the contact or it could be that you damaged the digitizer with the contact. I would probably take it to a place for replacement or to check the connection or you can tear it apart yourself. I personally would attempt to do a tear down on it and check the connection first it will save you some money if it is just the connection. But sounds like it is a bad digitizer. It is replaceable you will just need to do some research on finding the part for the replacement. Hope this helps.... Samsung j LCD SCREEN REPLACEMENT