John Bradshaw, in Healing the Shame That Binds You , calls toxic shame 'spiritual bankruptcy'. One can imagine a situation and feel deep shame. One can be alone and trigger a shaming spiral through internal self-talk. The more one experiences shame, the more one is ashamed. Guilt is more concerned with doing something, with transgressions, while shame is about a perceived failure of being, being unworthy, unwanted or bad.
Guilty people fear punishment.
Shamed people fear abandonment. Shame is not all bad, though. It can have great value if we are not overwhelmed by it. There would be no sense of privacy or intimacy without shame. Because shame is an uncomfortable feeling, a person who is not overwhelmed by it can use it to alter his or her behavior.