Self-compassion is a sympathetic response to your hurt, distress, or vulnerability, with a motivation to heal, repair, and improve. It brings a sense of empowerment — a feeling that you can do something to make your life better, even if you are not sure what that might be at the moment. It tends to keep you focused on solutions in the present and future.
Self-criticism is blaming yourself for your hurt, distress, or vulnerability, usually with a measure of punishment or contempt. It’s based on the mistaken idea that if you punish yourself enough you won’t make similar mistakes in the future, when just the opposite is true — self-punishment leads to more mistakes. (Who is more likely to make more mistakes, the valued self or the devalued self?) Self-pity is focus on your pain or damage with no motivation to heal, repair, or improve. It has an element of contempt for your perceived incompetence or inadequacy because it assumes that you can’t do anything to make your life better. Needless to say, self-criticism and self-pity turn pain into suffering.
— Steven Stosny, PhD, Living and Loving After Betrayal, p. 22-23