Traction control/limp mode/diesel filter overload

[Eric65]

I hit a rock coming out of a driveway about a week ago with my back left wheel. Nothing particularly damaging as far I could see and I was only doing about 2mph. The traction control hazard light appeared, quickly followed by the amber engine warning light. This has put my car into limp mode..... I am waiting for a chance to see a mechanic, but now an engine malfunction message has appeared and a message of diesel filter overload.... Are all of these related? On the internet I found that the traction control light would have been triggered by the traction sensors, which automatically send the message to the engine control to slow the car down (thus why it is in limp mode) so is it a case of checking and resetting the traction control message and everything should fall into place after that?? Or is there something more sinister? I don't want to spend a whole load of money on it as it is 15 years old.....