Citing a personal statement in a college application essay?

I'm a senior trying to figure out if I should reference my previous UCAS personal statement when writing my supplemental essay for a specific university. My counselor said I can't just copy-paste it, but I'm confused about whether mentioning my prior application counts as a self-citation or if I should just weave the experiences into the new text without formal attribution. I need to know if there's a standard way to handle this overlap without sounding repetitive.