Here's an interesting mental exercise:
Think of someone you love. A partner, or close family member. Picture them in an uncomfortable situation. A time when they were in a job they hated, or a situation when they felt out of their depth. Perhaps an occasion where they were humiliated or made a fool of themself. Don't you feel an overwhelming urge to rescue them? To hug them and take them away and make them feel safe? I know I do.
Now picture yourself in a similar circumstance. What are your thoughts now?
Mine are something along the lines of: "You IDIOT! How could you be so stupid? For pity's sake stand up for yourself!"
Self-loathing? Being one's own harshest critic? Perfectly natural self-defence mechanism? I don't know.