Part of an addict's issues is that they don't understand the pain that they've caused to others. Addicts are slaves to the flesh, self-medicating their own pain in alcohol or drugs or fantasy life (porn, etc.) and completely forgetting the trail of tears left behind. In fact, many addicts will repent of their sins and come clean, only to forget what is important and return to their selfishness.
I have a wife of 21 years and we have 8 children - 5 girls and 3 boys. They are all beautiful souls at their core, desiring beautiful things, but they are obvious products of pain and misery and it is pretty obvious that their father and husband has lacked the appropriate servitude and selflessness that should be evident in a Christian man's life, has in fact harmed them with spiritual abandonment, indifference, carelessness, selfishness, anger, and outright sin such as adultery.
I can just hear the choruses of "it takes two to ruin a relationship" and "she's probably got her problems, too, I'm sure." STOP. No, really, just stop. If you are thinking anything close to that in your head, then you likely have some issues in your own life that keep you from an appropriate level of responsibility to your own spouse and family, possibly God.
To meet the issue of addiction head on first, the addict must realize that they have an idolatry in their heart that causes a complete occupation with their god of choice - alcohol, drugs, porn, etc. The addict has a problem with worshiping the true God, and likely has pain that they haven't dealt with in its proper context, possibly blaming others and/or God for their problems. "If only he/she were more loving", or "if only I could get x, I'd be happy." What the addict is doing is replacing the true source of all joy and glory, and trading God for a cheap imitation. And similar to when Israel worshiped idols, their spiritual life suffered beyond hope, and with it, the families - just as they sacrificed their children to Baal, addicts sacrifice intimacy and sacrificial love for our families for the sake of serving ourselves. The family stagnates and gradually dies under these conditions.
The temptation is to react to large meltdowns in the family by focusing primarily on your family and desire to 'fix' things, and work harder to be the man that you are supposed to be. What you are in fact doing at that point is putting yourself in the place of God, denying the complete washing you need to receive by humbling yourself before the sacrifice on the cross, and finding yet another cheap alternative to true and deep healing. I can just imagine all of the addicts groaning and throwing their hands in the air, but there is only one narrow path that you can follow to true healing, and that is to restore your relationship with God, where the true focus belongs...
YOU NEED TO HUMBLE YOURSELF BEFORE GOD, and starting with the gospel, meditate heavily on the word of God and then in prayer name your sins and ask God to heal you from them, renouncing them as absolute 100% sin, and an affront to the blood of Christ. Ask God to restore a right spirit in your heart, and to restore a joyful relationship between you and Him. Our whole purpose is to glorify Him and enjoy Him, and you need to desperately seek God and ask for the strength to make that happen. Seek, knock, ask. And humble yourself. And ask again. And humble yourself some more. Every day seek God and ask for His cleansing power and for the ability to come before His presence and worship and love Him with everything you've got.
Yes, there are boundaries that need to be set, you need to do spiritual battle, and there are practical steps to combating sin in your life, but without the direct relationship with God being restored, all of these other resolutions and external-to-your-heart efforts will fail, because all of it is predicated on a right relationship with God.
The stronger your bond with God becomes, the more able you will be to serve and love your family. Sacrificially.
Ephesians 5:25-26 tells us husbands, "For husbands, this means love your wives, just as Christ loved the church. He gave up his life for her to make her holy and clean, washed by the cleansing of God’s word." If you have spent the large majority of your marriage dedicated to sin, then you have utterly failed in this manner. We are all supposed to be more Christ-like with every day that passes, and we should be seeking His word and His way fervently, and we should be bringing our families before the word - even more so with our wife, who should be "washed by the cleansing of God's word." Note that this scripture does not say 'shamed into submission by God's word' or 'corrected constantly by your brilliant exegesis and scholastic merit.' It says we should seek to make our wives holy and clean, and this language to me indicates the act of a Savior and Lord kneeling down to wash his disciples' feet, not dumping a bucket over their head and chucking a bar of soap at them.
If you have children, take an opportunity to bring them before God's word every day, in whatever simple illustrations you can give them for their age...
These words, which I am commanding you today, shall be on your heart. You shall teach them diligently to your sons and shall talk of them when you sit in your house and when you walk by the way and when you lie down and when you rise up. You shall bind them as a sign on your hand and they shall be as frontals on your forehead.… (Deuteronomy 6:6-8)
The word needs to be in your heart, and then you do your best to bring it to your wife and children, seeking only to humbly serve them, to lead the spiritually hungry to the bread of life. Not as one who is superior, but as a beggar showing others where to find food once discovered.
Do you see a theme here? What you need to do is realize the damage that you have done to your relationship with God first, and then your family. Then humble yourself. Bring yourself back to your Lord. Seek His word regularly. Allow yourself to feel the pain, and don't seek to medicate it anymore. Understand where everyone is at in their walk and fervently pray for healing in your heart and in their hearts. Be patient, it will take a long time, especially if you have been at your addiction for as long as I have. If you set expectations, you will push hurting loved ones further away from you. Just love and serve in whatever ways they will allow you. And humble yourself. Then humble yourself some more. And serve some more. And humble yourself even more. This is, I think the greatest formula for recovery for everyone involved in the addict's life.