phrasal-verb
dwell upon
過去に起こった嫌なことについて、あまりにも考えすぎたり話したりすること
Meaning
to think or talk too much about something unpleasant that happened in the past
Example
She tends to **dwell upon** her past mistakes instead of moving on.
彼女は過去の間違いを**悩んで**、前に進むことをしません