Humanae Vitae is online at the Vatican site, and the text highlighted below is © Copyright – Libreria Editrice Vaticana.
The other sacraments provide grace; we should expect it:
For this reason husbands and wives should take up the burden appointed to them, willingly, in the strength of faith and of that hope which “does not disappoint us, because God’s love has been poured into our hearts through the Holy Spirit who has been given to us.” (Rom 5. 5) Then let them implore the help of God with unremitting prayer and, most of all, let them draw grace and charity from that unfailing fount which is the Eucharist. If, however, sin still exercises its hold over them, they are not to lose heart. Rather must they, humble and persevering, have recourse to the mercy of God, abundantly bestowed in the Sacrament of Penance. In this way, for sure, they will be able to reach that perfection of married life which the Apostle sets out in these words: “Husbands, love your wives, as Christ loved the Church. . . Even so husbands should love their wives as their own bodies. He who loves his wife loves himself. For no man ever hates his own flesh, but nourishes and cherishes it, as Christ does the Church. . . This is a great mystery, and I mean in reference to Christ and the Church; however, let each one of you love his wife as himself, and let the wife see that she respects her husband.” (Eph 5. 25, 28-29, 32-33)
It would seem ancient Greek sexual roles are expanded for a mutuality here as we know and experience it in Western culture. That does not detract from mutual commitment and self-sacrifice. In a way, it completes it.