You ARE NOT a failure. You have tried something and it was tougher than you thought...it is not at all a reflection of your character. As a sociologist I explain a phenomenon to my students called the "Looking Glass Self" theory. It goes something like this:
Who we are (our self) arises from our interactions with others. We use society as a mirror (of sorts). In other words... First, we imagine how we appear to others...second..we wonder what they think about us, and finally...we determine how the first two make us feel...sad, embarrassed, happy, failure, etc.
Who we are... is determined by two things...Perception and Effect... how we perceive others think about us and the effect it has on our self esteem.
You see yourself as a failure because that is the perception you have from the most recent encounters you've had with the bakery customers...this in turn has effected your self-worth.
My point...this occurs even when we are wrong!!!! Others most likely see you as a success...you have your own business....a loving and supportive family...etc...however, you can only see things from the perception you have imagined...and it has effected your self-esteem.
You have had some extremely tough times recently and you have every right to feel bad about what has occurred. However, don't give up on the bakery until you are completely certain that is what you want.
My thoughts are with you through your struggle to find the right answer...but don't see yourself as a failure...you are the person who chased her dream....