If started to slow down eventually stopping, even though you are applying gas. Then there could be many reasons.
1st :- Dirty or broken gas/fuel pump. The gas/fuel pump is responsible for transferring gas/fuel from tank to engine.
2nd :- Loose wires in wiring harness.
3rd :- If the timing belt is off, even by one booth then it could also create problem in your car.
So it's better to take your car to good auto service shop. Because this thing can lead to any serious problem. If you are in Winnipeg then, i would suggest you to take your vehicle to Winter's Auto Service shop. Here you will get No.1 Car servicing at lowest price. The experts will check your car and give you best solution.