My STBX had an accident involving a very serious break requiring then surgery to fix and 2 additional surgeries. This took about a year. The initial surgery was clearly extremely painful and required pain meds. I was terribly worried about it and experienced the same thing you describe.
He milked the pain meds as long as the surgeon let him, took way too many and pulled the "this one doesn't work for me" so he could get additional prescriptions.
He even asked me to dole out his doses for the day because several times he had to go cold turkey for a few days until he could refill. But then he starting drinking too and searching everywhere for the meds so I gave up and let him do what he wanted.
When the pain meds were cut off he went full throttle on the alcohol.