Make your act of perfect contrition, and get to confession as soon as you can.
The act of perfect contrition, and the spirituality behind it, needs to be a blade in every Catholic’s “Swiss Army Knife” of absolutely necessary practices. I try to make all of my acts of contrition, acts of perfect contrition.
O my God, I am heartily sorry for having offended Thee, and I detest all my sins, because I dread the loss of heaven, and the pains of hell; but most of all because they offend Thee, my God, Who are all good and deserving of all my love. I firmly resolve, with the help of Thy grace, to confess my sins, to do penance, and to amend my life.
Perfect contrition in Catholic theology is a repentance for sin that is motivated by faith and the love of God. It contrasts with imperfect contrition, which arises from a less pure motive, such as common decency, or fear of Hell. The two types of contrition are distinguished by a person’s motive for repentance, rather than the intensity of ones feelings or emotions. It is possible for perfect and imperfect contrition to be experienced simultaneously. According to Catholic theologians, “all that is required is the standard of all human action, moral certainty.” A theologically sound “Act of Contrition” that is said with honesty and that reflects ones true intentions can provide the requisite amount of moral certainty. (Taken from Freebase, emphases mine.)