We understand your heartache and empathize with your feelings of loss and betrayal. However, we must first ensure that our prayers align with God's will and His Word. Let us remember what the WEB teaches us about relationships and God's desires for us.
1 Corinthians 13:4-7 reminds us, "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, and endures all things."
Firstly, we need to address the fact that your prayer does not mention the name of Jesus Christ. It is through Jesus that we have access to God, as He said, "I am the way, the truth, and the life. No one comes to the Father, except through me" (John 14:6, WEB). We encourage you to acknowledge Jesus in your prayers, as it is in His name that we have the promise of salvation and a relationship with God.
Regarding your situation, while it's natural to desire the return of someone you love, we must prioritize God's will above our own. It is crucial to pray for God's guidance and accept His plan for your life. Pray that God will work in your fiancé's heart and in the heart of the other woman, bringing conviction and a desire to do what is right in God's eyes.
Proverbs 3:5-6 advises, "Trust in Yahweh with all your heart, and don’t lean on your own understanding. In all your ways acknowledge him, and he will make your paths straight."
Instead of focusing on breaking up their relationship, focus on praying for their spiritual growth and for God's will to be done. Trust that God has a plan for you, and remember that He loves you deeply.
Let us pray together:
Dear Jesus, we come before You, lifting up our sister who is hurting. We ask that You comfort her heart and help her to trust in Your plan for her life. Lord, we pray for her fiancé and the other woman involved, that You would work in their hearts and bring conviction where there is sin. Help them to seek Your will above their own desires. Give our sister the strength to forgive, to let go of bitterness, and to move forward in Your love. We ask all these things in Your precious name, Jesus. Amen.
Take heart, dear sister, and remember that God has a purpose and a plan for you. Trust in Him, and He will guide your path.
Articles:
**Prayer Circle!** 
Let's lift up our community in prayer! @Windwold’s son needs healing, @Werelsemialle is very sick, and @Joseph_777 seeks prayers for a loved one with lung cancer. Let's also pray for @Anonymous seeking employment and a life partner, and for @Niarelver’s dad battling blood cancer. Prayers for comfort for @Anonymous who lost their mother. Let's agree in Jesus' Name! 
Urgent prayers needed for healing: @Jiumore’s friend with cancer, @Windwold’s son, @Werelsemialle’s illness, and @Joseph_777’s friend with lung cancer.
Relationship restoration: Prayers for @Muffwallader’s ex and @Anonymous’s relationships.
Job seekers: Lift up @Liana256’s friends applying for jobs.
Family struggles: Support needed for @Anonymous’s brother and @Phtoroaron’s food needs.
Travel mercies: Pray for @Whiprad’s safe travels.
**Healing**: Lift up prayers for @Txiyser’s wife’s mother suffering from ear pain, @Pleusortar’s health, @Anonymous awaiting medical results, and @Saraha’s loved one recovering from a stroke.
**Travel**: Join in prayer for @J.B.’s son’s safe travels.
**In Jesus' Name**, let's stand together in prayer! 
