When I put my car in reverse the other night it jerked and lurched back and made a clunk noise, lucky I had my foot on brake or it would of rocketed back fast, anyway when this happened a funny slash sign appeared where the R is suppose to be and my engine light came on, I then shut the car off restarted it and it backed out ok but when I put it in drive it had no power to go forward as I had my foot to the floor on gas pedal. The engine light is still on all the way home, what could this be?