There are several solutions to the problem of the self.
In Calvinism, the worthlessness of the self is simply a given. You don't have to worry about your worthiness, because all is forgiven if you recognize that you are worthless, and only saved by admitting it.
It doesn't seem very healthy. It seems, in fact, brilliantly perverse, because it is based on something very real: we are imperfect and know our imperfections perfectly well.
In modern positive psychology, the self must be bolstered ("self-esteem"). The problem here is that we know our selves too intimately, with all the flaws. Holding up and affirming the self constantly gets very tiring. For people who haven't accomplished very much yet or who have experienced trauma, wounds to the self. the idea of self-esteem seems like a lie. On the other hand, self-esteem allows narcissists to simply float along with a false sense of merit. (Although they also have to do a lot of work to make sure other people recognize their merit!).
In zen, the self is unknowable or doesn't exist. You don't have to be bound up, then, with either a sense of inherent depravity (Calvinism) or with a struggle to keep your finger in the dike all night, the existential threat to the self. After all, if you have high self-esteem, then there is always the risk of having low self-esteem, if you don't know how to sustain it on a daily basis. It seems better to put more effort into helping other people than in endless "self-improvement."
You can still have a basic sense of self-worth based on the idea that everyone has value, and the secondary self-esteem based on real accomplishments. You can be proud of things you've done, or take pleasure in doing things well, that you know how to do. But the self is already beside the point.