God bless you my brother, and welcome to the journey of a lifetime! It is so fulfilling to see any Protestant, many of whom know and love Our Lord so well, to come to the fullness of the faith, His One, Holy Catholic, and Apostolic Church. And you are quite right, the Holy Spirit has led you to this point, where the scriptures have been opened to you, and you are blessed with the gift of being able to see that the Catholic Church is the Body of Christ. Welcome!
Like a previous poster said above, make sure you pray before you speak to your pastor. I would call and arrange a short meeting. You do not have to explain to him beforehand your reason, just say you would like to see him. When you talk to him, make sure you are clear that your decision is based in scripture and prayer, that you love your Christian background but that you are SURE that you have found the fullness of the faith in the Catholic Church. Be very kind and thankful, after all this man has apparently been very helpful to you in your journey with Christ.
The key is to be very loving and thankful to him, but also very firm that you KNOW this is the truth. If you water down your feelings, he may feel that you are unsure about your decision and try to convince you otherwise.
I am so happy to hear this story. I will most certainly pray for you in your meeting with you pastor and your faith journey. You have many blessings in store, my friend. And make sure you do not worry. "Pray, hope and don't worry. Worry is useless. God is merciful and hears our prayers." -St. Padre Pio
God is with you in this beautiful decision, trust Him :) Also, feel free to message me if you would ever like to talk, ask questions, etc. about the faith.
Peace and blessings,