Repent in the shower and realize the sinfulness of fornication. Repent of your loved one, if you committed the sin of fornication against him. Honestly tell him about the reasons that led to the fornication, about your feelings, experiences, emotional state. Apologize to him and try to gain back the trust and love, from whom you fornicated. Not maintain any connection with the person with whom you have sinned, and try to avoid even the hint that you can once again do that sin. Behave decently, not to let even the slightest reason your loved one to doubt the sincerity of your repentance. But never let yourself down, do not tolerate mockery of moral or physical punishment.
Try to explain that you are fully aware you have committed sin and are ready to redeem it. Focus on what you honestly confessed to fornication and now regret committing such an act. Remind your loved one that you are constantly punishing your conscience that it doesn't give you a second to forget about your accomplished sin.
Go to Church, if you want to atone for the sin of fornication before God. Confess to priest, do not need to hide anything, tell us all about it, not priukrasit your story and don't try to achieve understanding. Repent the priest's soul, and acknowledge the sinfulness of fornication. Never fornication, abstain from temptations and committing sinful acts. Start living a proper human and Christian life, often confess and live according to Church laws. Do not allow despair, which also is a very big sin at the source of which is human pride. Find out from the priest of order of Holy communion and make sure that you start to constantly partake.