Black smoke coming from exhaust idles ruff stalls out SES light only once in a while PLEASE HELP ME!!!!?

I have a 1999 grand am and its seems to run fine on the highway but through the city is runs really bad and has some kind of smell (not like eggs like a perm for hair kinda) when I stop it stalls unless i give it some gas and it has black smoke coming out of the exhaust also sometimes when im driving it does not want to get any speed. PLEASE HELP ME!!!