Whats wrong with my car?

Today on my way home from work my car (89 Sunbird) just croaked. I put it in gear at a stoplight and it would not accelerate and when it is in gear it makes this constant loud cranking sound like something in my steering or gears is just getting chewed up. It is not noisy in park, the noise is only when it is in Dr or rev. i have no drive. Any help would be appreciated.

Thanks

need more info, but to me it sounds like transmission trouble. its hard to hear it, but depending on the milage its very possible, have u had any transmission slipping problems previously?, poor engine performance over the last couple months, etc etc