We are truly saddened to hear about the strained relationships you have with your sons. Let's bring this situation to the Lord in prayer and seek His guidance and wisdom.
Firstly, let's remember what the WEB says in Malachi 4:6, "He will turn the hearts of the fathers to the children, and the hearts of the children to their fathers." This is God's desire for families, and we trust that He can bring healing and restoration to your relationships.
Regarding your estranged son, we pray that God would soften his heart and open the doors for reconciliation. Remember, it is only by the name of Jesus that we can be reconciled, that nothing can separate us from the love of God. Romans 8:38-39 says, "For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, nor height, nor depth, nor any other created thing, will be able to separate us from the love of God, which is in Christ Jesus our Lord."
We also pray for your oldest son, that God would convict his heart and help him see the importance of honoring his parents, as commanded in Ephesians 6:2, "Honor your father and mother," which is the first commandment with a promise.
Let's pray together:
Dear Heavenly Father,
We come before You today, lifting up this parent who is feeling alone and worthless due to the strained relationships with their sons. Lord, we ask for Your healing and restoration in these relationships. Soften the hearts of these sons, and help them to see the love and sacrifice that their parent has made for them.
Father, we also pray for this parent, that You would strengthen them and give them the wisdom to navigate these difficult situations. Help them to remain patient and loving, even in the face of disrespect and rejection. We know that it is only through your Son, Jesus Christ, that we can pray to you with confidence.
In Jesus name, we pray for this family, asking for Your will to be done in their lives. Bring peace, healing, and restoration, Lord. Give them the grace to forgive and to be forgiven.
In Jesus name, we pray. Amen.
Lastly, we encourage you to continue to pray for your sons and to trust in the Lord. Remember that God is faithful and that He cares for you and your family. Stand firm in your faith, and do not give up hope. God promises in Romans 5:8, "But God commends his own love toward us, in that while we were yet sinners, Christ died for us." In this verse we are reminded that God loves us when we do not deserve His love. We also know that forgiveness is possible when we believe in Jesus Christ.
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. 
