미안해. 그동안 잘 못 챙겨줘서.
I translated this as "Sorry. For not caring all this time".
I know that subject pronouns in Korean can be confusing. But when I cross-checked this with Papago and Google, I get results as "Sorry. I haven't been able to take care of you" and "Sorry. For not taking good care of me all this time."
Would my translation be more accurate given that it is apathetic to the subject?