So by your admission, the parts not in bold are correct. To reitterate, that would mean the following is true.
Martin then approached him from behind and said "Yo, you got a problem?" Martin then said "Well, you do now" and punched Zimmerman in the face. Zimmerman was knocked to the ground while Martin got on top of him and started hitting him and bashing his head into the ground. Zimmerman says that when Martin saw his gun he tried to grab it saying "You're going to die tonight, motherf***er" so he only fired the gun in self-defense, believing his life was in danger.
And since that is true, Zimmerman's life certainly was in danger meaning this entire case never should have happened.
A glance at the rest of the questions is the truth that the frenzied mobs screaming racism can't accept.