Dream of apartment, building

I was in a large building possibly an apartment complex with a group of people everywhere i looked there were people murdered and murdering others i realized that my only option was survival as the dream progressed i found myself killing others, my weapon of choice was a knife but i had a gun. i could hear the knife sinking into the flesh of those i killed i was killed at one point, by a chainsaw but came back as if nothing happened i woke after i drove my knife into someone\'s back as i slept i could feel my body shaking uncontrollably