I am in some distress. I desire to go back to the Holy Eucharist, but I have messed up my marriage with an out of wedlock son. I have made my wife cry a lot, but†she doesn't know about the child. She does know about the child's mother. I am hating myself and wonder how I sunk so low. I have stopped the extra marital affairs, but I need to seek forgiveness. Do I confess about the child to her, or by going to a priest, confessing, and sincerely changing. Then the church will allow me to have the Eucharist. Is this being hypocritical? I have started attending therapy sessions, which I will attend with my wife. How much should I disclose? We have three beautiful children and married for about a decade. I am so ashamed. What will God do to me? What curse am I placing on my family? Why am I the weakest point?
I will talk with you about your problems and help you understand what God wants you to do, but I want you to understand at the outset that I am not Catholic; I am a Christian and teach people the Word of God. "If anyone speaks, let him speak as the oracles of God. If anyone ministers, let him do it as with the ability which God supplies, that in all things God may be glorified through Jesus Christ, to whom belong the glory and the dominion forever and ever. Amen" (I Peter 4:11).
You sunk so low because you put your desires in front of everything else in your life. "Therefore, since Christ suffered for us in the flesh, arm yourselves also with the same mind, for he who has suffered in the flesh has ceased from sin, that he no longer should live the rest of his time in the flesh for the lusts of men, but for the will of God. For we have spent enough of our past lifetime in doing the will of the Gentiles -- when we walked in lewdness, lusts, drunkenness, revelries, drinking parties, and abominable idolatries" (I Peter 4:1-3). If you want to reach heaven, then you need to become a true Christian, not someone claiming to follow Christ while going your own way. See "Are You a Christian?" and "How to Become a Christian" for more on this subject. The important point is that if you decide to change, to God it doesn't matter who you were, but who you are. "Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God. And such were some of you. But you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus and by the Spirit of our God" (I Corinthians 6:9-11).
In regards to your marriage, you have made a mess of things. You violated the covenant you made with your wife, sworn before God and witnesses on earth. I'm glad your wife is willing to try to work out the problems you caused, in that she is upholding her part of the covenant.
Since your wife knows who the other woman is, then it follows that she will eventually know about the child you produced with that adulteress. In addition, because the boy is yours and innocent in this matter, you have a responsibility to the child. You took on that responsibility when you chose to have sex with that other woman. It doesn't matter whether you intended to have a child or not. You made your choice when you unzipped your pants. Therefore, your problem now also becomes your wife's problem. You must be responsible for the raising of this child. That is going to impact your time and your expenses, which will impact the rest of your family. How you and your wife settle the matter with the adulteress to the best interest of the child is not something I can comment on since there isn't enough information. Experience tells me that you and your wife will have to endure a lot of stress before this issue is resolved.
What your wife doesn't need to know are details about your affair. She'll want to know why you bedded another woman, but in that process she'll unfortunately try to compare herself to the adulteress. You ruined the trust in your marriage. Don't destroy it further by telling your wife the details. Tell her you were wrong. Tell her that the flaws are yours alone and that you are ashamed about your weakness and sins. But don't even hint that she had any responsibility for your miserable choices and don't allow her to compare herself to the other woman by giving her details about what you did.
I don't know your wife. I don't know if she'll be able to forgive you. She ought to. It is what God requires of her, but you can't make it happen. It is something that she will have to work out on her own. However, you can make it easier for her by radically changing your behavior. Justifiably, the greatest fear is the question of whether you will do it again. If you are truly ready to repent, then that change needs to show up in all aspects of your life. "For godly sorrow produces repentance leading to salvation, not to be regretted; but the sorrow of the world produces death. For observe this very thing, that you sorrowed in a godly manner: What diligence it produced in you, what clearing of yourselves, what indignation, what fear, what vehement desire, what zeal, what vindication! In all things you proved yourselves to be clear in this matter" (II Corinthians 7:10-11). You have a lot of bad habits that need to be broken quickly and completely.
I know I haven't mentioned anything about confessing to a priest or rules about whether you can partake of the Eucharist. These are things not found in the Bible. They are man-made things added by the Roman Catholic church. See "Why did Catholicism start and when did it happen?" for a list of additions the Roman Catholic church introduced. Also, see "What is wrong with the Catholicism?"