We understand your heartache and commend your steadfast love and commitment. We will address the concerns you raised. We will pray for your partner, and for you, that God's will be done in both of your lives.
Firstly, we need to address the spiritual aspect. You mentioned that your partner is an unbeliever, and this is a significant concern. As it is written:
Do not be unequally yoked with unbelievers, for what fellowship do righteousness and iniquity have? Or what fellowship does light have with darkness? What agreement does Christ have with Belial? Or what portion does a believer have with an unbeliever? But you are a chosen race, a royal priesthood, a holy nation, a people for God's own possession, that you may proclaim the excellence of him who called you out of darkness into his marvelous light. 1 Peter 2:9 WEB
We must rebuke you for this relationship. This is not a relationship that is honoring God or a godly marriage. It is outside the will of God to be unequally yoked with an unbeliever.
You mentioned that you are living in sin with your partner. We must address this and rebuke you for this. Fornication is a sin and you both are sinning against God and each other by not being married.
Marriage is to be held in honor among all, and the bed undefiled: but God will judge the sexually immoral and adulterers. Hebrews 13:4 WEB
You mentioned that your partner is reluctant to get married. This is not the biblical design for relationships. The goal of courtship should be marriage, and it is clear that your partner does not share this goal. We must rebuke you for this and encourage you to seek a relationship that aligns with biblical principles.
Your partner's struggles with addiction and mental health are indeed serious concerns. However, it is also written:
Hope in God, for I will still praise him, my Savior and my God. Psalm 42:5-6,11; 43:5 WEB
Come to me, all you who labor and are heavily burdened, and I will give you rest. Take my yoke upon you, and learn from me, for I am gentle and lowly in heart; and you will find rest for your souls. For my yoke is easy, and my burden is light. Matthew 11:28-30 WEB
We pray that your partner will turn to Jesus, the one who can truly heal him and set him free from his addictions. We pray that he will find rest and peace in Him.
We must also address your partner's history of infidelity. This is a grave sin and a direct violation of the Seventh Commandment.
You shall not commit adultery. Exodus 20:14 WEB
We pray that he will repent of this sin and turn to Jesus for forgiveness and healing.
Many of the problems you mentioned are due to your partner being an unbeliever. This is why it is so important to be unequally yoked with an unbeliever. We pray that your partner will come to know Jesus as his Lord and Savior.
We need to address your statement I hate his lack of faith.
Love is patient and is kind; love doesn't envy. Love doesn't brag, is not proud, doesn't behave itself inappropriately, doesn't seek its own way, is not provoked, takes no account of evil; doesn't rejoice in unrighteousness, but rejoices with the truth; bears all things, believes all things, hopes all things, endures all things. Love never fails. 1 Corinthians 13:4-8
It is important to remember that love is patient and kind, and that it does not take account of evil. We must rebuke you for this hatred and encourage you to pray for your partner with love and kindness.
We must also address the sexual sin that was committed against your partner by a priest. This is a grave sin and a direct violation of the Seventh Commandment. We pray that your partner will find healing and forgiveness in Jesus.
Finally, we want to address your statement that you could just walk away, but you do love him. We commend your commitment and love. This is why we are rebuking you for your unequally yoked relationship and fornication.
We pray that God will give you the strength and wisdom to make the difficult decisions that lie ahead. We pray that He will guide you and your partner into a relationship that honors Him.
Father, we lift up this couple to You, asking for Your will to be done in their lives. We pray for the salvation of the one who is living in rebellion and for healing from the pain and anguish that have kept him bound. We ask that You break the chains of addiction and mental health struggles, and that You bring him to a place of repentance and surrender to You. We also pray for the one who is seeking Your will, asking that You give them the strength and wisdom to follow You, no matter the cost. We ask all of this in the name of Jesus Christ, who made our access to You possible.
Prayer Focus: God, Thank You for loving me. God, I ask You in Jesus’ name please bless me with everything that I stand in need of and everything You want me to have. 
