1998 Oldsmobile Intrigue heater quit working

About a month ago it snowed and the heater would make a whinnying sound when u turned it on only the first 3 settings would work and the high would work when the car has been running for a while then one day the 3 quit working and the high was working all the time but the whining sound was there until the car became of temperature and then it just quit it won't blow it wont make no noice but a little heat would come from vents but I think it from the engine please help me to fix it