2015 Chevrolet Colorado drivetrain & axles problems

While stopped and trying to turn left on a busy highway I was hit from behind by a driver who did not see me until it was to late. I saw him in my rear view mirror, however, barreling down at me at a high rate of speed. I hit the gas to the floor trying to get away from him but my 2015 v6 colorado hesitated for a 1/2 second or 1 second, I don't know. It seemed like forever. It then kicked in and we got about 100' before he slammed into the right rear bumper.

When driving at low speeds, it feels like the transmission is in the wrong gear, because when you need a fast acceleration, the car bucks and almost feels like it's going to stall. It seems like it is searching for the right gear and therefore it takes time to react. I have been on a few close calls, almost got into an accident a couple of times because of this bucking and delay on reacting when you need to get the power from the engine.