1991 Chevy Caprice when idiling it chugs, lack of power for

When it idles it chugs then when I satrt driving it chugs also I noticed a lack in power ill put the gas pedal down more then it will finally kick in after a few seconds, I also smell rotten eggs it feels like something is clogged I dunno I was told it could be a number of things etc. Catalytic converter, fuel filter, egr valve, or even spark plug wires, bad gas mileage, I just dont wanna guess and end up paying more money thank u very much for your time