Guns not shooting correctly. Help.

For some reason, where I aim is not where my bullets go. Whenever I fire a weapon, the bullet goes to wherever I first shot the weapon. It doesn't matter if the target is right in front of me, it will just not hit. Also, I cannot use my favorites to switch weapons. I must use the inventory menu. Any clues as to what is going on? I am not running a melee build, so this is really hampering my combat abilities.