2003 Chevy Cavalier surging, rough idle, and sometimes stalling when A/C is on. IAC valve issue? Compressor fan? Compressor? Or could a car in need of a simple tuneup act like this?

Not mechanically inclined but I'll try to provide as much info as possible. I have 2003 chevy cavalier 4 door. I'm not exactly sure when this issue started but it is A/C related so I only noticed it a few weeks ago upon turning the A/C back on. When the car is idling at say a red light or in park the rpms surge a lot but only when the A/C is on. Turning the heat on doesn't seem to cause the same effect nor does simply having the fan on or none of the above. The rpm's surge causing a rough idle and at times for the car to stall. I had the unfortunate pleasure of experiencing this while turning into a parking space, felt like I lost power steering at the same time. The rpms actually hit 0 but the car was not completely off. The radio and other gauges were still functioning. Just no power to the engine. My car has an old R-12 refrigerant system so I got an adapter, oil, and some 134 refrigerant. Had someone show me how to do this but he stopped shy of putting the refrigerant in as the car kept surging and the A/C temperature seemed to actually get a bit warmer. After leaving though I left the A/C on and the thing was nice and cold while driving. Parked my car and the air seemed far warmer, the rpm's also starting surging all over the place after about a minute or so. Seems like there is a hissing noise around my glove compartment like air pushing out of something(he said it could be an actuator?) but I hear the hissing far more during the surging period when the car is trying to compensate and bring the rpms back in range. The interval between the surges is 5-10 seconds once it gets going. As is my car idles at around 600rpms which seems low, surges to about 900, drops to nearly 400 before going back to 600 if it hasn't stalled by then. Trying to narrow it down. Please help.