What's a word/phrase like "compulsion" or "addiction" that is more about guilt than physiology or anxiety?
You might like compunction
Defined by Merriam Webster as:
1 a : anxiety arising from awareness of guilt < compunctions of conscience >
b : distress of mind over an anticipated action or result < showed no compunction in planning devilish engines of … destruction — Havelock Ellis >2 : a twinge of misgiving
And by Dictionary.com as:
- a feeling of uneasiness or anxiety of the conscience caused by regret for doing wrong or causing pain; contrition; remorse.
- any uneasiness or hesitation about the rightness of an action.
Consider hang-up [MWD]
something that causes you to feel worried, afraid, embarrassed, etc.
Alternatively, you could use feeling of obligation [TFD]
A social, legal, or moral requirement, such as a duty, contract, or promise, that compels one to follow or avoid a particular course of action
You could say
I know the drought is over, but I still have a hang-up about putting a bucket in the shower, and using that water to flush the toilet.
or
I know the drought is over, but I still have a feeling of obligation to put a bucket in the shower, and use that water to flush the toilet.
You should consider obligation (optionally preceded with moral).
M-W:
obligation noun
: something that you must do because of a law, rule, promise, etc.
: something that you must do because it is morally right
She believes that all people have a moral obligation to defend human rights.
He argues that people in a community have certain obligations to each other.