Advice for an issue with my car?

Planning to schedule an appointment with my local service station when they open tomorrow... can someone tell me about this issue I'm having in the mean time?I was out today having a leisurely drive in my Volvo S80 from 2006 which is a high mileage car (252k miles on it) and suddenly there was an issue where the car would dial up the acceleration to 5 or 6 on the dial while the car was struggling to keep up with 20 mph going uphill. The issue progressed throughout the day to the point where I will put my foot on the gas and and it wouldn't "go" at all. The car is struggling to keep up and keeps revving constantly when I put my foot on the pedal without actually going anywhere. I was able to get it back to my place by turning the car off and on. In the road with my blinkers on, which is really not safe.Any suggestions for fixes? via /r/cars http://ift.tt/2tvTyoM