2000 Ford Ranger vehicle speed sensor?

I own a 2000 ford ranger with the 3.0L v6. Recently my mother drove to the airport (about an hour and a half drive for us) and got cut off by some woman in front of her and had to slam on the brakes. This resulted in the ABS light on the dash to come on. Well on the way home the truck started having trouble accelerating and shifting gears. When I went out to check things out. The check engine light and and the ABS light were both on. I took it for a test drive and found that the speedometer was not working well and the transmission was shifting into any and all gears for no reason. Needless to say I borrowed the diagnostic machine from my work and (i work at a quick lube) it read the code from "vehicle speed sensor". I pressed the reset button and have been afraid to test drive for fear of causing permanent damage to the transmission. I was also told that this sensor doubles as an ABS sensor and that was the reason for the ABS light. Im just curious if resetting the light will be enough or if I need to replace the sensor itself?