Car Idles low and high on 1997 Toyota Camry

The past few weeks I've been having idling issues. When I'm stopped at a light, the car at times idles low at around 800 rpms, then can jump to 1200 rpms. This morning at a light, it dropped to about 400 and was shaking like it was going to stall then spiked to 1200 before coming back down. At times when I take my foot off the brake, sometimes my car jumps forward ready to take off before I hit the gas. When I got home this evening, I put the car in park and it was idling between 1200-1400 rpms. I had it at the dealership last week and they suggested a dirty throttle body. My husband cleaned it yesterday and said it wasn't dirty. This idling issue is getting worse each day. Any ideas?

Asked by for the 1997 Toyota Camry
Might be the Idle Air Control (IAC) Valve. Are you getting a Check Engine Light (CEL)?