No, you don't need a license to defend yourself. If you are being attacked and a weapon is accessable, be it a pistol, rifle or shotgun, and you use it to protect your life or the life of a loved one anyone who thinks you've done wrong is an idiot. Be well prepared for that idiot though because they are everywhere and a number of them are running this nation.
You're going to have some serious questions to answer for if you defend yourself with a weapon that was hidden on your person without the proper license. I don't agree with the license but until it changes I pay the $90 every 5 years so I stay within the laws.