help! rpm revs up and won't shift gear
 

this is 1999 civic dx sedan ( automatic ), after drove about 30 miles, stopped the car for few minutes and after start the car, engine is revving up in park and I can't shift out of park without using the override. It works fine after you shift out but afraid to drive it. When it goes back in park, the engine revs to a higher RPM again and I can't shift out of park.

no check engine light for now, can't think of anything.. please help