I think you should not be looking for a “key” to changing your life, but rather a “keyring”. It should have been obvious not just from the myriad answers you got here, but from the reading of Scripture you had quoted.
The verses you quoted are near the end of 1st Corinthians chapter 13, St. Paul’s famous Canticle of Love, where he extols the different virtues attached to love, and that even the greatest of the virtues, the theological virtues of hope and faith, are useless without love. From this passage of Scripture St Thomas Aquinas surmised that the virtue of love, or charity as it is traditionally known, is the form of all virtue. That is, the virtue of charity “informs” the other virtues to what end they should lead to, which is God Himself (ST II-II Q. 23 A. 7 and 8). But since you cannot practice all the virtues at the same time, it falls to the virtue of charity, the “Keychain” of virtues, to decide which virtue should be strengthened and practiced at every stage of the Christian’s life.
In the beginning, love wants to know its Beloved, so Faith and Vocal prayers are the beginning of the spiritual life, and the active life protects and bolsters it. As the Christian progresses, mental prayer and finally contemplative prayer are reached. All of these were mentioned by the posters above, and they should correspond to which stage of the Christian life you are in.