2001 Volvo S40 Car shakes when slowing down

For sometime now when driving and Slows down, my car shakes until I push the clutch down. And the engine is idle you still hear the engine sounding high and low.

Please let me add this. How does the aircondition fan works? With mine it does not work with the thermostat, it comes on and off on its own and in traffic hold the ac stops cooling.
My AC Expect says when the discharge get hot it cut off the cooling.

Need help all over the world, besides I love my Volvo and love to enjoy it to full. If you know how I can pay for technical support from Ghana. Let me know (k_agyapong@hotmail. Com)

Regards

K. Oxo - Ghana