2003 Vauxhall Astra light on dashboard and engine making noise

My car was driving fine on the motorway and then suddenly a light on dashboard came on with a car and a spanner running through it. It stayed on for a while and then intermittently it comes on an off. At first I thought I'd check it out when home as not overheating but I turned down my music and then noticed my engine being very noisy and worried me to the point that I thought that anything could happen. I thought it best to turn round and limp home. I have only had the car a couple of months and I am not familiar with engines and what the lights mean. If anyone could give me an thoughts of what it might possibly be I would be grateful. Thank you.