Truck does not stay running after starting it?

My truck doesn't stay running after starting it. Maybe 2 minutes max then the engine shuts off. No electronics are affected lights etc. For context a few days ago I flushed my engine before I changed the oil because it was darker than normal. Then I was driving on it fine all day until I was on the way home and I braked, it shut off on me. Ever since it just doesn't stay running now. So, I'm not sure if the flush messed up the truck? Or maybe a bad fuel pump? But how does that explain why it was running all day after the oil change? I can record a video or facetime someone to show the issue.