Indeed, my friend.

But Galatians 1:12 also needs Galatians 1:18 and following:

Galatians 1:18–24

[18] Then after three years I went up to Jerusalem to visit Cephas and remained with him fifteen days. [19] But I saw none of the other apostles except James the Lord’s brother. [20] (In what I am writing to you, before God, I do not lie!) [21] Then I went into the regions of Syria and Cilicia. [22] And I was still unknown in person to the churches of Judea that are in Christ. [23] They only were hearing it said, “He who used to persecute us is now preaching the faith he once tried to destroy.” [24] And they glorified God because of me. (ESV)

Galatians 2:1–2

[1] Then after fourteen years I went up again to Jerusalem with Barnabas, taking Titus along with me. [2] I went up because of a revelation and set before them (though privately before those who seemed influential) the gospel that I proclaim among the Gentiles, in order to make sure I was not running or had not run in vain. (ESV)

Paul received his Gospel from Jesus, but Paul also made sure it was the same Gospel preached by the Apostles.

Paul makes it clear with his statement that the faith he once tried to destroy, he now preached.

It wasn't a new faith. He wasn't proclaiming a different messages to the Twelve.

He was proclaiming the same faith he once tried to destroy, the same message the Apostles proclaimed.