gun dream

Hi,ok, I am 18 and a female. I like to consider myself hard core, because I love to play with guns, and go hunting and im trying to get into the border patrol... Last night i had a horrible dream. I woke up with my heart racing. My Dream started off at night in a car dealership. I along with other people were security guards for the place. I was in a car while some others were on foot. I spotted a guy standing there in my light and yelled out him . "hey... " he then took off running to the left, and i was standing on the bridge. The one on foot took after him and i told him which way he ran, a couple min later i herd a gun shot and i pulled my weapon. Two other security officers came by my side. The guy came back looked at me and shot. He missed me by a couple inches to my head and made a hole in the brick building. His gun, thank god, only held one bullet at a time, while mine held two. I shot at him and missed. He ran behind cover and so did i, to reload. In this room, which is by the way in back of where im standing, i am loading my gun when i hear another shot ring and my partner flys back into the room with his leg shot off. I will spear u the details, but my dream didn't to me... I saw everything, felt everything, and even cried. I was freaking out, and the other guy came by his side to help him. The thief/bad guy shows up in the doorway and shoots my other partner and kills my partner with his leg blown off.. I scream horrified... He looks at me, walks back out and reloads his gun (comes back in and shoots me... ) the part in () is what i kept playing over in my dream, but changed everytime... the next time, ( came in and i shot him in the head)... and the last time, ( came in as i was waiting for him hiding, and shot him in the leg, blowing his off. Jumping on him and handcuffing him!) .... I then woke up scared to death, sweating, and my heart beating out of my chest!!!! I really need your help to tell me, what that dream was about. I am soo freaked out!Thanks