Information is not some simple variable without context, it always exists in relation to some function/task/conflict.
Our "state of mind" is a question of what we're engaged in, the frame against which information is defined. And pain is information, plain and simple.
It does not follow that we can simply wish pain away; there are always constraints on what actions we can take. It is nonetheless possible though to achieve at least some degree of "mind over matter" insofar as we can find alternate pathways of action with different criteria of what constitutes relevant information.
Psychic anguish can most definitely be related to physical pain because we act and by extension perceive in relation to conflict.
It's not that the psychic anguish is directly causing physical pain like a billiard ball hitting another, it's that it becomes part of the ground against which our somatic figure is defined.
In these cases one must find a narrative to enact that renders such ground irrelevant.
Some things are so deep in the body that we have no volition over the millions of micronarratives beneath the skin, but sometimes we have the option of changing the rules of the game.