Engine light on and car will not go faster than 30 mph

So I’ve had no problems with my car
and then all of a sudden today the
engine light came on and the car
would not go over 30 klms an hour.  I
drove with my hazards on to a shop
and I’m scared to find out what they
are going to say as being a middle-
aged woman and totally naïve about
cars and I know we get ripped off.  I
turned the car off and started it up a
couple times but that engine light just
stayed on and like I said would not go
home over 30 km an hour.  I would
appreciate any feedback  someone
knows what this is about .... kindly ~
Shannon