So consider (as Cromwell so memorably said) that you may have been imperfectly catechized or have a misunderstanding regarding your early teachings. Don't know how old you are, but if you were in CCD back in the 60s or 70s, many parishes fell prey to relativism and a desire to 'fit in' by being as 'mainstream' as possible. So a lot of folks were mis-instructed or not instructed at all.
Fwiw, not only is there Scriptural support for Purgatory (e.g., 1st Cor 3:15, 2nd Macc 12:43), but sacred tradition and the earliest writers of the Church confirm it - St. Augustine, Tertullian, Cyprian, Clement of Alexandria. Sacred tradition is present in all churches, Catholics just acknowledge it and conserve it.
And Purgatory does not conflict with salvation or the concepts of grace or faith -- it is simply a cleansing, the tree lies where it falls. Have you read C.S. Lewis's The Great Divorce? Splendid book with some very illuminating thoughts on heaven, hell, and purgatory -- and Lewis was an Anglican.
On my Catholic education:
8 years Catholic grade school
4 years Catholic high school
weekly CCD classes by quite conservative Novus Ordo RCC priest
parents subscribed to National Catholic Register, the Wanderer, Fidelity and The Remnant, and I read them while growing up
my parents fought the Novus Ordo modernism tooth and nail and are now in the SSPX - I would politiely challenge you to ask them if they considered me to be inadequately catechized
I subscribed to Fidelity and Remnant in undergrad college and never stopped contending against modernism in the Catholic Church
Yes, on 1 Cor 3:15 and Maccabees, I was thoroughly catechized in those passages. “And as it is appointed unto men once to die, and after this the judgment.” Heb 9:27
I got saved when God convinced me that only Christ’s death is acceptable as full payment for my sin.