1992 Pontiac Grand Am Stalling and Revving

I am writing from Canada yet we are having quite a mild winter this year. It is only -10 degrees farenheigt tonight. Im not sure if this is part of my problem or not. My car is doing a number of strange things.
1. When I step on the gas pedal after idling the car seems to "stick" ; it takes about five seconds to react and the RPMs go way up anywhere from 3000 to 4000 and really revs up, then when it does react to my foot on the pedal and speeds up the RPMs go back down to about 1000. Also when it finally does speed up it seems to do so very suddenly, it kind of jerks ahead.
2. When stepping on the brakes; ie- at a red light, the car seems to struggle to keep from stalling; lights dim, shakes mildly, grunts a little etc, and sometimes it does in fact stall if I step on the brake too suddenly/not gradually enough.

I only seem to have these problems when driving between 1-40 or 50 Km per hour.

Any ideas?