It is an inner sense of being completely diminished or insignificant as a person. It is self judging self. It is the ongoing premise that one is fundamentally bad, inadequate, defective, unworthy or not fully valid as a human being. When you take the life of an unborn child, you devalue that life. In turn your inner respect for the value of your own life and others is diminished.
Shame is a matter of one's identity.
Guilt allows for confession and cleansing. Ending shame requires an entire system change or spiritual transformation. God has designed us to enjoy perfect freedom with each other and with Him but many cannot. We are very excellent actresses. We can produce false personalities and then hide behind them, hiding hurts, pretending we don't need anyone, when reality says otherwise.