When you are baptized a Catholic you remain a Catholic. You can always come back to the church. Sit down with a priest and get answers to your questions about Purgatory.
BTW, Trinity is not in the Bible either, but we all believe in God the Father, God the Son and God the Holy Spirit.
There are many references to Purgatory from the Old Testament throughout the New Testament.
Name them. I have read the Bible through from Genesis to Revelation several times and I have NEVER seen even a hint of a reference to purgatory.
However, it does say that when we die we either Immediately go to heaven if we have accepted Jesus as LORD and Savior, if not, we go Immediately to hell, NO inbetween.
Jesus did not go to purgatory to preach to the captives there. He went, as he told the thief on the cross, to Paradise. Which was in the same area as Hell, but a large, deep gulf separated them. When he ascended back to heaven he took those who were in Paradise with him. It’s in the Book.