I tried a new recipe for a fondant that didn't turn out very well. Can I make it into a poured fondant?

No - Fondant is just sugar and water cooked to a solid mass and kneaded so that the sugar recrystallizes into a smooth, "melt-in-the-mouth" product. This is used as fillings in confectionery. Pouring fondant is fondant gently heated with water to a liquid consistency. This is used as a cake covering glazefor items such as petit fours.

Rolled fondant has other ingredients in it's make-up, that make it unsuitable to be rendered as a glaze.