I was totally wrong! I already had the part and I was able to reattach the derailleur. Thank you everyone for the help! However, problem 2. This is why I was confused. The back wheel is now uneven, because of the space created by the derailleur nut & bolt. I am unfortunately out of pieces now... what do I need to put on the other side of the frame to create the same amount of space? This is the space I am talking about: http://i.imgur.com/GaXzwjQ.jpg