I read the comic Seconds, by Bryan Lee O’Malley, the same author of the Scott Pilgrim series.
The comic is a quick read. The main character is Katie, the head chef at a popular restaurant. She meets the restaurant’s house spirit, and Katie is given a magical mushroom that lets her redo events that happened in the restaurant (or rather, the mushroom sends her to a world in which she made a different decision). Katie finds more mushrooms, and uses them in an attempt to build a perfect life. Katie is rash, impulsive, and a bit self-absorbed, so she needs to consume a lot of mushrooms to fix her mistakes.
In the end, after abusing the mushrooms and destroying the fabric of space and time, Katie reverses all her changes. She learns her lesson, and her life ends up exactly as she wanted it to anyway. Everyone gets a happy ending.