I think I've answered my own question.
Our "physical part" doesn't think on its own. Every sensation in our body is a "perception" by the brain. In order to take command of feeling hung over, dope sick, or any other kind of bad, one must take control of their perceptions of discomfort and how to deal with them.
In early withdrawal from opiates, I did turn to my question "What would a non-opiate-user do?" And the answer was NEVER to use more opiates.
Okay.
Well, maybe my question will help others sort this out for themselves.
FT