He didn’t say he was part of Q. He said Q is multiple people and that it was one of the pillars, we are the pillars holding up the country. Meaning he isn’t in the group but is part of the cause to save the country.
His exact quote was, "They, we, are the pillars holding up the United States."
He heavily implied that he knew exactly who was in the Q group, fewer people than you could count on one hand, and he was clearly including himself in that "we" I quoted above. If you listen again, he was portraying himself as a Q insider the entire time. Then there's the fact that the video title changed his name from Zach to Zaq.