1998 Honda Civic Very Low Idle

I have a 1998 Civic EX with a 5-speed trans. At times, my engine idle starts to go very very low. The car will shake a little bit from it going so low. It happens usually when I am sitting at a stop light, or I just sit still at all. Sometimes, my engine will shut off when I am turning a corner. I'm not really sure of the problem here. I almost thought it was an alternator issue, but not sure. The idle is also effected by the headlights turning on and applying the brakes.