Issue while driving for a long distance

I have a Honda Accord 2002 4 cylinder automatic, since the past 3 weeks, I have been having an issue with my acceleration. The car begins to jerk and doesn't gp beyond 30MPH when I drive it for a long time and stop. When I drive for a long distance like 40 miles and then stop at a red light, it begins jerking violently when it turns green and I apply gradual pressure to the gas pedal. It also doesn't speed up more than 30MPH unless I change from D4 to D3. Once I change that, it accelerates well and speeds up pretty smoothly. When I am driving withing town there is little jerking. i had an oil leak that was fixed just before this issue began. When I showed it to a mechanic he said the car seems fine and nothing is wrong with it.When it begins jerking violently, I change it from D4 to D3 and that seems to solve the problem for a while.