for like a decade I kept getting the advice of "don't ruminate" but also "sit with your emotions" and I was like What The Fuck Does That Even Mean. until someone finally explained it in a way that makes sense:
so there's the emotional part of your brain ("I'm embarrased") and then there's the storytelling part ("all my friends hate me and I'm a piece of shit"). when people say "don't ruminate" what they mean is don't feed the storytelling part
you tend to the emotion ("I'm feeling x. why am I feeling that? how do I move forward given that information? what's something nice I can do for myself right now to cope with this?") but you treat the storytelling part like a little goblin that's trying to be as unhelpful to this whole process as possible. this doesn't shut the storytelling goblin up completely, but it keeps it from causing so much chaos and over time it stops talking so damn much
it's basically like if you were trying to comfort a friend. you'd validate their emotions, but you wouldn't sit there and let them call themself a piece of shit. do that for yourself
sharing this in case someone else is also like Why Didn't Someone Just Say That