Wendy! I hope you didn't throw it away!!! THAT was your sourdough. Was it a blackish-grey type "hootch" on top??? You just stir that back in and away you go
Try it again..........maybe you do need a tad cooler place, it sounds like the "beasties" in sourdough got out of hand.....but sourdough is tough stuff. I did the exact same thing you did. Used rye starter......everything going okay, til it got blackish water on top and icky-smelling. Don't leave it out so long. After day 2...I'd toss half of it...and stir in some fresh flour. That will ensure its nice and active, but not so active that the sugars have been converted into alcohol.
If you want a FABULOUS FREE starter.......send a SASE to Oregon Trail Sourdough. It was started by an elderly man, Carl Griffith (who has since passed away). He gave away thousands of sourdough starts from his family's recipe (dates back to 1847). Now since he's passed.....the "friends of Carl" make sure his legacy continues. Here's the link.....I use this starter weekly and it never fails to make world-class bread. Another book you might like, if you're into bread is "The Bread Baker's Apprentice" by Peter Reinhart. He has a recipe in there for pain l'ancienne that is out of this world.http://home.att.net/~carlsfriends/