What does this dream mean?

I was on a school bus, talking to my friends, and everyone was moving slowly (outside the bus). It was very hot. When me and my friends were joking about them, we realized they were zombies. I was sitting about 3 seats back from the bus driver (where i usualy sit in real life) (and this is not my neigborhood though. It is somthing my mind made up.) i and yelled for her to go to the safe house (like it was normal for zombies to attack). When we got there it was dark. It was a nice house, like in a middle cl town. Not some shelter. There were no zombies arroundd yet, but i knew they were coming. The buss driver and some other adults set up a plastic table, with sme tortilla chips and salsa (i have no idea why) and a bucket with water bottles in it. I grabbed 4 or 5 and was walking to the front door t get in and hide when my friend calle dme back to the table, tellinng me that i would regret not eating, so i started stuffing my face cuz i didnt want to stave in hiding. So i saw the zombies coming with torchecs in a large group coming from the right (when my back was to the house). I yelled for everyone to get in the house and i started running to the door. I was locked and i noticed everone was running twords the garage door. So i started trying to run, but i couldent move fast. Everyone elkse was running, but it was like i was stuck in somthing. Then i woke up. Its like no matter how hard i tried to be prepared, it wasnt enough.What does it mean?