Overheating

whilst in a traffic jam in birmingham this afternoon i noticed the needle on the temp guage was into the red, i pulled into a shopping centre and lifted the bonnet ,i still had water and there wasnt any steam. so decided to drive back to telford. on the motorway the needle went up every time i accelerated so crawled back. with needle about halfway up the guage then about 10 mles from home the needle stuck on red at the sae time the rev counter needle kept dropping to zero and then going back up again. i pulled off motorway and left it at a garage that was about to close so i wont know anything until monday ,any ideas as to if this is going to be painful. any thoughts greatfully received am really worried.