Here is the Catechism cited in chapter 1 of Experiencing Grace in Abundance.
982– There is no offense, however serious, that the Church cannot forgive. “There is no one, however wicked and guilty, who may not confidently hope for forgiveness, provided his repentance is honest.” Christ who died for all men desires that in his Church the gates of forgiveness should always be open to anyone who turns away from sin.
1450-1458 – “Penance requires…the sinner to endure all things willingly, be contrite of heart, confess with the lips and practice complete humility and fruitful satisfaction. 1451 the penitent’s acts contrition occupies first place. Contrition is ” sorrow of the soul and for the sin committed, together with the resolution not to sin again. 1452 When it arises from a love by which God is loved above all else, contrition is called “perfect”(contrition of charity). Such contrition remits venial sins; it also obtains forgiveness of mortal sins if it includes the firm resolution to have recourse to sacramental confession as soon as possible.1453- The contrition called “imperfect” (or attrition) is also a gift of God, a prompting of the Holy Spirit. It is born of the consideration of sins’ ugliness or the fear of eternal damnation and other penalties threatening the sinner(contrition of fear). Such a stirring of conscience can initiate an interior process which, under the prompting of grace, will be brought to completion by sacramental absolution. By itself however, imperfect contrition cannot obtain the forgiveness of grave sins, but it disposes one to obtain forgiveness in the sacrament of Penance.1454 The reception of this sacrament ought to be prepared for by an examination of conscience made in the light of the Word of God. The passages best suited to this can be found in the moral catechesis of the Gospels and the apostolic Letters, such as the Sermon on the Mount and the apostolic teachings.1455- The confession of sins, even from a simply human point of view, frees us and facilitates our reconciliation with others. through such an admission man looks squarely at the sins he is guilty of, takes responsiblity for them, and thereby opens himself again to God and to the communion of the Church in order to make a new future possible. 1456-confession to a priest is an essential part of the sacrament of Penance; “All mortal sins of which penitents after a diligent self-examination are conscious must be recounted by them in confession, even if they are most secret and have been committed against the last two precepts of the Decalogue; for theses sins sometimes wound the soul more grievously and are more dangerous than those which are committed openly. 1457- According to the Church’s command, “after having attained the age of discretion, each of the faithful is bound by an obligation faithfully to confess serious sins at least once a year.” Anyone who is aware of having committed a mortal sin must not receive Holy Communion, even if he experiences deep contrition, without having first received sacramental absolution, unless he has a grave reason for receiving Communion and there is no possibility of going to confession. Children must go to the sacrament of Penance before receiving Holy Communion for the first time. 1458-Without being strictly necessary, confession of everyday faults (venial sins) is nevertheless strongly recommended by the Church. Indeed the regular confession of our venial sins helps us form our conscience, fight against evil tendencies, let ourselves be healed by Christ and progress in the life of the Spirit. By receiving more frequently through this sacrament the gift of the Father’s mercy, we are spurred to be merciful as he is merciful.
1468– The whole power of the sacrament of Penance consists in restoring us to God’s grace and joining us with him in an intimate friendship. Reconciliation with God is thus the purpose and effect of this sacrament. For those who receive the sacrament of Penance with contrite heart and religious disposition, reconciliation is usually followed by peace and serenity of conscience with strong spiritual consolation. Indeed the sacrament of Reconciliation with God brings about a true spiritual resurrection, restoration of the dignity and blessings of the life of the children of God, of which is the most precious is friendship with God.
Whew, did you get all that? God loves you. No matter what. Go to confession, at least once a year.
I used this edition of the Catechism: