Your prayer to return to your first love is beautiful and it is exactly what the Lord delights to answer. We love because He first loved us, and when we remember how great His love for us is, our love for Him is rekindled. The call in Revelation is to remember, to repent, and to do the works you did at first, and that is a gracious invitation, not a heavy burden.
Choosing the better part as Mary did is at the heart of it. To sit at the feet of Jesus in humility, to listen to His Word and to give Him undivided attention, is the place where love is restored. That posture will not be taken away from you. It means intentionally putting away distractions and sin and asking for protection from the evil one, so that your heart is free to be with Him.
Prayer in that place is more than asking for things. It is communion with God, talking with Him, sharing your heart, expressing your love, worshiping and adoring Him. As you keep yourself in the love of God by praying in the Holy Spirit, you are built up in your most holy faith and Christ is more at home in your heart through faith. You become rooted and grounded in love. My prayer for you is the same as Paul prayed, that your love may abound more and more in knowledge and in all discernment, that you may know by experience the breadth and length and height and depth of the love of Christ. The more you come to know Him and His love for you, the more your own love for Him will grow in response.
Remember the order of grace and peace. You cannot know true peace until you have first received grace, and we stand only by grace. God has called you with a holy calling not because of your works or worthiness but because of His own purpose and grace given in Christ Jesus. Your righteousness before God is not your own, it is His righteousness given to you through faith in Jesus, because He gave Himself once for all for the forgiveness of sins. That is the glorious gospel of grace to hold fast to, adding nothing to simple faith in Christ.
From that place of love and grace, the outward life flows naturally. Love for Jesus overflows into love for His people and for those who do not yet know Him. It expresses itself in edifying the church, in comforting and encouraging others, in sharing the testimony of what Jesus has done, and in making disciples by teaching others to obey all that Christ commanded. This is how the work multiplies, as those who are taught become faithful and able to teach others also, and God is glorified in His church through Christ Jesus.
I thank God for the work His Spirit is already doing in you and I pray for you with joy. I ask the Father to give you extra grace and discipline to pray, to study His Word, to worship, and to walk in holiness with the fruit and gifts of the Spirit. May He fill you with goodness and faith and power, so that the name of our Lord Jesus Christ may be glorified in you, and you in Him, according to the grace of our God and the Lord Jesus Christ. May your love abound and your life bear witness to His power from on high as you share the good news with others.