Question:
Answer:
First off, God bless you for having a sensitive conscience and thus recognizing your grave wrongdoing.
Go to confession as soon as you can and confess this mortal sin and receive absolution, and do not receive the Eucharist again if you happen to participate Mass in the interim.
Know that our Lord is rich in mercy and so desires to have you reconciled with him, as the parables of the Prodigal Son (Luke 15:11-32) and the Lost Sheep (Luke 15:1-7) illustrate so well.
In preparing for confession, I encourage you to read the Catechism of the Catholic Church’s presentation on the sacrament of reconciliation (CCC 1420ff.) and particularly regarding the acts of the penitent (CCC 1450ff.). In addition, if needed, ask your faithful Catholic friends to recommend a good priest confessor. During confession, ask the priest what are some good ways to help avoid the specific mortal sin you committed.
God bless you in walking with the Lord, and remember that it is always better to struggle with sin than attempt to rationalize your sins and therefore make a false peace with them.