My ex girlfriend caused a shooting?

Date: 6/28/2018

I had a dream about an abusive ex of mine. We suddenly ran into each other and decided to go to my old high school and pretend that we were students there. She kissed me and we told each other jokes and laughed and it was all wonderful like I remember all the good days with her being. Then out of nowhere the principal announced over the speaker that we had 5 minutes to exit the building or we would "become a monster." We all ran out screaming and there was a guy there with a gun and he started shooting at all of us. I was shot but I wasn't killed so I just laid there next to all the kids I used to go to school with. When he turned around and moved onto a different time group of kids I was able to stand up and try to run. I saw my stepdad with him, holding a gun. He put his finger up and shushed me so I wouldn't say anything. I think he was there to protect me. Then the man saw me running and started laughing and pulled out a can of gasoline. He started spraying it at me and everywhere all over the building. I tried to run but I wasn't fast enough. I remembered being burnt when I was younger and I started screaming for my stepdad to help. I asked him to just shoot me if he couldn't save me because I didn't want to die this way. Then I woke up. I don't understand if the end was related to the beginning or if it was all random. Either way I miss my ex now and although I know she was terrible to me, I want her back.