From my coaching certification:

Remarkably, studies have found that negative self-talk and negative social judgement — aka self-criticism — is often physiologically worse than physical stress. Every time you or your clients criticise yourselves, you create a “real” bully that actually physically harms you.

Research compared people who had been wounded by criticism and social disapproval, and people who’d been actually, physically wounded in a natural disaster.

In terms of the long-term trauma, people who’d survived the proverbial acts of God were better off. After all, a flood or famine isn’t personal. It just happens. But social disapproval disapproves of you personally as a human being.

Let it sit with you for a moment.

That’s right: Being mean to yourself can be worse, physiologically speaking, than an earthquake.

Luckily, being mean to yourself is a habit. It's a habit you can break.