Ford Focus car running badly, lacking power, vibrating

I was overtaking a car and as i put my foot flat to the floor the car slowed down apposed to speeding up eventually it did struggle to overtake, the whole way home the car had a significant vibration I assumed it was a wheel bearing or track rod end. When I arrived home I left the car idling and realized when i got out that the exhaust was vibrating and looking under the bonnet i noticed the engine was too. It sounds like the timing could be out or a misfire could have occurred, the car is severely down on power and the fuel consumption is very poor. If anyone can shed some light on the situation it would be greatly appreciated thanks.