2001 Mercury Sable brakes and engine

Hello, I was backing my car up and all of a sudden it just felt like I had run out of gas but my car did not shut off. The engine was sputtering and my brakes became super hard to push in. I drove to the gas station and applied gas. It didnt fix the problem. It drove home perfect besides the brakes. I noticed the check engine light came on when I pulled into the driveway. The next morning when I cut on the car and popped the hood the engine is shaking and muffler sounds like its coughing and I hear light pops every 4-5 seconds. Checked all my fluids and there fine please helpppp.