Worth is objective. Human worth is based on the imago dei, that is being created in the form of God. I believe shame, guilt, and feelings worthlessness come from feeling the reality of falling short of living up to the image of God which our worth is based on.
Christianity allows a person to acknowledge the guilt of falling short and gain a sense of self-worth not from any human aspect, but from the perfectly lived life Of Jesus Christ. This allows self-criticism without guilt, because one's self-worth is dependent on someone else.
It's really amazing to see this lived out.