耿耿於懷

耿耿于怀
gěnggěngyúhuái
to take troubles to heart (idiom); brooding

CEDICT

to brood on; to not forget about a matter and always be troubled or vexed by it

Wiktionary

有心事牽絆，不能開懷的樣子。宋．文天祥〈賀前人正〉：「某跡縻俗駕，心遶賀星，遙指於軫中，拳拳公壽，雪立殘於門外，耿耿於懷。」也作「耿耿於心」。

重編國語辭典

有事牽絆，不能開懷

維基詞典

Entry Composition

1 耿耿 gěnggěng
  1. bright
  2. devoted
  3. having sth on one's mind
  4. troubled
2 於 yú
  1. (of time or place) in; at; on
  2. (indicating any indirect relation) to; toward; vis-à-vis; with regard to; for
  3. (indicating a source) from; out of
  4. (used in comparison) than
  5. (used in the passive voice) by
3 懷 huái
  1. bosom
  2. heart
  3. mind
  4. to think of
  5. to harbor in one's mind
  6. to conceive (a child)