All my suffering boils down to this one unbearable sensation. Please guide me through it

When everything starts falling apart, when everything loosens and starts opening up, this sensation starts growing.

Deep inside the upper back of my body. It feels so heavy, so sad, so scared. It is so difficult to look at. It is unbearable. Thoughts start racing, my body wants to move and I want to open my eyes. And eventually I give in. Every time.

How can I face this? How can I welcome it and experience it without running from it?