Consolidate your verb tenses a bit. Since you're giving advice about what to do before parents die, it sounds strange using the past and past perfect.
"You should provide each and every convenience and comfort to your aging parents. If you
didn'tdon't do this, you wouldwill regret it after they haddie d".
It looks like maybe you were trying to use the present unreal conditional, but that's used to talk about what you generally do in imaginary situations. In this situation, you're attempting to give advice in the present.
Student or Learner