Here’re some words from the Catholic Catechism:
2218 The fourth commandment reminds grown children of their responsibilities toward their parents. As much as they can, they must give them material and moral support in old age and in times of illness, loneliness, or distress. Jesus recalls this duty of gratitude.23
Code:
For the Lord honored the father above the children, and he confirmed the right of the mother over her sons. Whoever honors his father atones for sins, and whoever glorifies his mother is like one who lays up treasure. Whoever honors his father will be gladdened by his own children, and when he prays he will be heard. Whoever glorifies his father will have long life, and whoever obeys the Lord will refresh his mother.24
O son, help your father in his old age, and do not grieve him as long as he lives; even if he is lacking in understanding, show forbearance; in all your strength do not despise him. . . . Whoever forsakes his father is like a blasphemer, and whoever angers his mother is cursed by the Lord.25
2222 Parents must regard their children as children of God and respect them as human persons. Showing themselves obedient to the will of the Father in heaven, they educate their children to fulfill God’s law.
2223 Parents have the first responsibility for the education of their children. They bear witness to this responsibility first by creating a home where tenderness, forgiveness, respect, fidelity, and disinterested service are the rule. The home is well suited for education in the virtues. This requires an apprenticeship in self-denial, sound judgment, and self-mastery - the preconditions of all true freedom. Parents should teach their children to subordinate the "material and instinctual dimensions to interior and spiritual ones."31 Parents have a grave responsibility to give good example to their children. By knowing how to acknowledge their own failings to their children, parents will be better able to guide and correct them:
For me, the words “as much as they can” is key. You don’t want to confirm someone in their abuse by just being a doormat and taking it, but you do need to honor them.
That’s my understanding though. Maybe it’d help to ask one of the apologists on this website. My parents have been abusive towards me, but I decided to call them once a week since I live far away - across the country-- from them. I didn’t want to become an old bitter person and forgiveness helps me let go of resentment. However, I can’t talk to them for too long or visit much because of the distance and because it reopens old wounds. I try to always say “I Love You” to each of them. I know it isn’t much, but at this time, with God’s help, it’s all I can do.