Is insulting one's honor considered slandering chaste women and a major sin, even if it was not intended to accuse the family of indecency but rather to insult them as a reaction?

Swearing at someone who swore at you is permissible in principle, as long as the wronged person does not exceed the limit. This is indicated by the Prophet's (peace be upon him) saying: "The two who exchange insults, whatever they say, the sin is on the initiator, unless the wronged one transgresses." And Allah's Almighty saying: "And those who, when tyranny strikes them, they defend themselves. And the recompense of an evil is an evil like it. But whoever pardons and makes reconciliation - his reward is due from Allah. Indeed, He does not like wrongdoers." However, forgiveness is better. As for swearing with slander and insulting a person's family, that is forbidden. If you impugned his lineage, then you have erred. The principle for a Muslim is to help other Muslims and to make way for a passerby on the road, as long as it does not harm him.