1098T and 1099Q: lifetime learning credit and self-beneficiary of my 529

I am a grad student. My tuition was  $20,000 for 2021. I withdrew $4,000 out of my state 529 to help pay for tuition and books, so I got a 1099Q. I am a self-beneficiary of my 529.

I read that I don't have to report my 1099Q because I used all of the distribution for qualified expense, my tuition and books. 

 

 Can I still claim the lifetime learning credit because I still have remaining total qualified expense after help from my 529?
 $20,000 total educational expenses 
-  $4,000  distribution from 529

$16,000

 

Of that $16,000,  can I claim 20% of it up to $10,000 so $2,000? Of my educational expenses, $1000 was books.

 

Additionally, this was the same situation for last year, but I didn't claim the lifetime learning credit because I was worried about double dipping. Can I use TurboTax to do an amended tax return for 2020?

 

Thank you very much!!