Seperation is a rough thing to go through. I went through a very similar thing myself in my marriage. Draw close to the Lord, study His Word, and depend on Him for all things. His Word tells us, "seek first Gods Kingdom and His righteousness, and all these things will be added to you". If you will focus on God and your relationship with Him, not only will your family witness the change in you, but, you will be the spiritual head of your home, even a seperated home. Your boys will see this and with your prayers for them, they will return to the Lord. Who but God knows, your wife may see this and wish to reconcile. Either way, pray with your boys and over them, show them the change that God has made in you, and they will seek Him also. We have the promise that if we train our child up in the way they should go, they will not depart from it. Ask each one for forgiveness, and confess your sins to them. Dont forget to forgive yourself, and dont keep yourself in bondage with unforgiveness. My prayers are with you, and I pray for a healing in your relationship with God, your wife and your sons in Jesus precious and Holy name, for the Glory of the Father, giving Him praise for this.