2002 Renault Laguna low revs, battery light telling me to stop, think its only working on 5 valves instead of 6

hi, my car has the battery warning light saying please stop, also its revs are low, when first driving away its low but if put foot down it changes gear ok, car shudders when driving, and when its stood still,engine light on on dashboard, comes and goes, also telling me anti pollution dont know what that means , car starts ok