Praise God for your conversion and his work in your life! Thankfully, there is no sin or evil that we choose that is beyond the Lord’s mercy, provided that we turn away from it with sorrow and humbly ask for His forgiveness. The Lord can surely forgive your decision to get a tattoo that is evil or contrary to the Christian faith.
I have heard of similar situations where people have had the tattoo removed OR had an artist “Christianize” the current tattoo. This can relieve you of a permanent reminder of the Occult and instead, you’ll have a reminder of Christ the Victorious King who conquers all evil.
If you are Catholic, I highly encourage you to visit with your local priest in order to renounce your past involvement with the Occult. We have some beautiful and powerful prayers that were specifically written to break any bonds, promises, or oaths that may have invited demonic influence in a person’s life. This is a powerful spiritual remedy and can provide a greater experience of the freedom that the Lord Jesus desires for your life.