Hi Darklight,
The issue you have posted about is not a rare one at all for new Catholics. I encourage you to discuss this with your RCIA group during your Mystagogy sessions. But I will share some of my thoughts with you.
First of all, are you happy you are Catholic? Congratulations on your one week adventure in being new in Christ!

Whether you choose to inform your parents in person, or to send them a card or note, I would like to suggest that you first prepare yourself spiritually. Doing so will help you to open up your mind and heart toward your parents.
I’ve served the Church for years, and try to remember to pray first, and do whatever else that is necessary spiritually to prepare. As for matters of faith, it’s been more challenging for me to deal with family than with anyone else! And for some reason, knowing that I should pray first, I forget too much of the time, and I end up regretting not being better prepared spiritually, to be better able to reflect the love of Christ for them.
Remember “Darklight” that you are no longer the person your parents think they know. You are wearing a new garment in Christ; you have become a new creation. Through Baptism your soul is infused with faith, hope and love, and our Lord’s Holy Spirit wants to help you use the seven wonderful gifts endowed on your soul to build up Jesus’ Kingdom here on earth – which includes those two beautiful creations called parents who allowed you to be born! The gift of the holy Eucharist has provided you nourishment and strength so that you can strive to be one, not only with our Lord, but with everyone else the best way you can, including your parents.
Remember why you’ve done all this studying, praying, and working at letting God transform your heart, mind and will in Him. Remember His love for you! and that you love Him! Remember your joy in knowing this, and knowing how important you are to Him! Remember you are glad that you are Catholic, no matter what anyone else thinks about it! Remember how grateful you are to be a member of the holy Church our Lord founded for us all, to help us to get to heaven. Remember the hope that you have, to share the eternal banquet table with all the angels and saints – and that you want your loved ones there too! Let them witness your happiness. Love your parents here and now, no matter what – try your best to lay aside all their imperfections and undesireable behaviors.
Remember that Jesus was criticized and spurned repeatedly during his public ministry. He even enraged many in his hometown of Nazareth (see Luke 4). You can approach your parents remembering you are not the old “kid” any more. Be confident (not arrogant) that Christ is WITH you. You are holy. You can choose to BE a Christ to them! Don’t let their approval or disapproval matter so much any more – that’s a worldly thing. Just be loving. No matter how they choose to respond, no matter the criticism, the emotions, the fallout, the unfairness, or how you feel. That’s just junk – dust – which you can shake off your shoes.
I remember having to tell my mother something difficult, many moons ago, which I dreaded. I first dwelt on all the possibly negative ways she would react, because I considered her deficits, and I was a mess after all that dreading. So for a day, I considered things I appreciated about her – I’m thinking of her pumpkin spice nut bread as I type this – looking for the goodness in her helped me to prepare more positively. Look for the goodness within your parents, and even if they behave in a negative way, continue to look at the good. Your parents will always be your parents, you can continue to love them and remember their dignity and yours, no matter what. Jesus didn’t argue with people – He accepted that some people would not accept Him or what He had to say. That’s what Jesus wants from you. He didn’t stop loving people when they spurned Him. I’d like to think that some of those in Nazareth’s synagogue who ran him out of town later got curious, and followed him.
So, piece of cake, right?! No, of course not. And no matter how you approach your parents, you will probably inform them imperfectly, and they’ll respond imperfectly. There might be an earthquake, but be calm – stand with God. Look at your behavior, not theirs. And then there’s that glorious gift of unconditional forgiveness! And the gift of praying for those we love. And the gift of God’s many graces, including the sacramental graces which sustain us. Please remain clothed in Christ. That’s the daily (hourly) challenge for each of us who has been baptised.
Thank you “Darklight” for loving God! He has special plans for you, each day. May you and your parents be blessed in the light of our Lord’s love.
Psalm 46
God is our refuge and our strength, an ever-present help in distress. Thus we do not fear, though earth be shaken and mountains quake to the depths of the sea, though its waters rage and foam and mountains totter at its surging.
Streams of the river gladden the city of God, the holy dwelling of the Most High. God is in its midst; it shall not be shaken; God will help it at break of day. Though nations rage and kingdoms totter, he utters his voice and the earth melts. The LORD of hosts is with us; our stronghold is the God of Jacob.
Come and see the works of the LORD, who has done fearsome deeds on earth; who stops wars to the ends of the earth, breaks the bow, splinters the spear, and burns the shields with fire;** “Be still and know that I am God! I am exalted among the nations, exalted on the earth.” The LORD of hosts is with us; our stronghold is the God of Jacob.**
Some other passages to prayerfully reflect on:
Philippians 4:4-9
Colossians 3:12-17
1 Peter 1:13-16