Forgetting Potion

[hgallego]

10-15 years ago I read a short story in French (not sure if that was the original language) about a forgetting potion. A man is driven to despair after being left by his lover. At this horrible moment of despair he creates a potion to forget everything from the present to the moment just before he met her. However he miscalculates the strength of the potion. He only forgets to the moment of maximum despair where he again decides to create a potion to forget the affair. And again the potion takes him back to the moment of maximum despair. He therefore becomes trapped in an endless loop of pain.

Does anyone know this story or who wrote it? I have been trying to find it in vain for many years.