The mystery of God’s mercy is indeed profound and worthy of contemplation. It is good for us to set time aside on our calendar and focus especially on that mystery and what it means for us. In particular, I think it is helpful to remember that Christ died for us while we were still sinners (cf. Rom 5:8). He took upon himself our sins, and his death is the means by which those sins are wiped away.
Usually, we go to the sacrament of Reconciliation during the Lenten season (though this year that prospect has been somewhat more challenging). By this sacrament our sins are forgiven and we prepare ourselves to celebrate Easter with a heart that is made clean so that no stain of sin blocks the graces God wants to bestow on us in the gift of his son. Just like we might shower and groom ourselves before an important interview, so we desire to meet the Lord with a clean soul and orderly heart.
But I think it is important to remember that we cannot merit God’s grace. Our acknowledgement of our sins and the desire for repentance comes only after God has already begun the work of conversion in us through the death and resurrection of Jesus Christ. Out of love for us, Christ died on the Cross, and it is his love that now moves us to go to confession. The sacrament of Reconciliation is a response to his love. We would not be able to go make a good confession unless he was first at work in us calling us to go (and conversely, if we never feel called to go to confession, we might wonder if we are suppressing the voice of God in our lives).
This response to God’s love and mercy is part of the reason why it is fitting that Divine Mercy should follow on the Sunday after Easter. It is a response on our part to acknowledge what God has done for us while we were yet sinners and to seek a deeper conversion. God first loved us and enables us to love him in return (cf. 1 Jn 4:19).
Of course, this does not mean that going to confession before Easter is wrong. We should still properly prepare for the sacraments and making frequent confessions is good and helpful. But let us remember this Divine Mercy Sunday that our love does not merit God’s love, but is itself a response to him loving us first with the greatest of love.