Shuts off while driving and cruise control stopped working

My car has developed an idle speed problem, before it was doing it only occasionally, where it would shut off if I took my foot completely away from the brake. Now it does it constantly, with an added problem: The Cruise Control will no longer engage. The light on the "on/off" switch turns on to show that it is at least active, but when I try to set my speed, the car ignores it. Are the two problems related? Losing my cruise control isn't a deal breaker per se, but the idle speed is an issue I have yet to get taken care of (other things have gone out on the car that required more immediate attention, like an alternator I recently replaced and a cracked wheel that failed and took the tire with it).

What are my possibilities?