Car feeling sluggish after a very sudden stop.?

So my car (2002 Toyota Highlander V6 Limited) suddenly wouldn't pick up speed at an intersection while I was driving. The RPM was increasing as I was putting more gas but the car wouldn't go past 20 MPH so I pulled over and turned the car off and checked the engine. Nothing seemed wrong so I started the car again and it was running again. A check engine and VSC light I had on before from a damaged sensor (which has been there for about 2-3 months now) went away but the car feels much more sluggish after this incident. I feel like the car is much heavier and I need to push down on the pedal for it to pick up speed. Also, I haven't done an oil change in a while. Could this be the problem?