SCIENCE: I thought I'd share a little bit of info which I tell students in the positive mindset workshops I do. Understanding this might help you gain a bit of relief and perhaps put some perspective in place when negative thoughts are heavily clouding your happiness.
When we were hunter gatherers the average age of death was 30yrs old, that's because so many kids died before they reached the age of 15 so it brought the average right down. But you could have lived to 60yrs if you'd been really, really good at one thing: focussing on negative situations.
Being hyper aware of negatives like the threat of starvation, violence and disease (the 3 biggest killers) meant that you were more likely to survive. Those, that managed to survive, had kids and through natural selection (Darwin rocks!) those kids then went on to be even better than their parents at focussing on the negatives and so on and so on through the generations. So we have actually evolved to be really bloody excellent at rooting out and focussing on negatives.
But now we (most of us) don't have the threat of starvation, disease and violence every day so our brains focus on any negatives they can find. And because of the pressure these days those negatives might be thoughts about our bodies, our abilities, the impact we are making, our achievements.. etc. Because we aren't gonna get eaten by a bear- those are now the negatives which our brain's enlarge to the point we feel like we are suffocating.
When you think about it, it's your brain trying to keep you safe. Doing what it is magnificently evolved to do. So when you are able to pull yourself out of the fog, maybe thank your brain for trying so hard to keep you safe but then tell it to calm down a bit. You've got too much stuff to do.
Science thanks to Clifford Nass, Professor of Communication from Stanford University and beautiful stylised brain drawing by @artworkbyemilie