Stoicism is just sparkling loneliness.

Stoicism is just dissociating philosophically

I wanted to smack this one coworker so damn hard. He shouldn't shut up about it like it was the answer to all my problems, and I'm just standing there like, "You mean the thing I've been doing literally most of my life?!"

I think the idea is that, when you're judging yourself really hard for something you've done, you're asked to consider what you would think of a friend who had done the same thing. A lot of the time people would view the friend as having a made a forgivable mistake, even though they're treating the behavior in themselves as evidence of an irredeemable and permanent character flaw. So it's like, use supportive language when you talk to yourself. Remind yourself of all you've done right and all you've overcome, that sort of thing. Forgive yourself and build yourself up. It's a specific instance of the kind of labeling-and-countering you're talking about.

The point is to be kind to yourself. You should be honest with your friends, but you should make efforts to frame that honesty in a caring and positive light, ensuring them that they're safe with you and that you're raising your concerns out of love for them.

The therapist's point is that most people know to treat they're friends that way, but tend to be much harsher and less generous with themselves. So: cut yourself some slack, is the message.

That sounds dangerous and isolating.

As someone who grew up constantly criticized, still no idea

Just what I always needed! Condescention and dismissal!