Hyundai and Cylinder #1 and #2 Misfire

I have just bought a 5-speed 1997 Hyundai Elantra with 110,000miles. I believe it has started a few miles after I hit a speed bump underneath the car and ever since that it has sounded like a misfire. I went to an Auto Shop for the tester and found 2 misfires in cylinders 1 and 2. I changed the spark plugs, and the wires thinking it would help and yet it did the same thing. I have an exhaust leak and don't know if the speed bump was the problem. Now my car only goes about 5 miles an hour, if I rev it up enough it will go to 30 miles an hour in first just so I can move it. After moving it, now it barely starts and I'm unable to go anywhere.I'd be greatful to figure out what is wrong with the car.