Where in databases? ( retrieve custom CSS changes that got lost)

Hi!

I need help. This is nightmare coming true. :_(

I did everything right. Child theme. But once I changed something in the functions.php file i had a fatal error and got locked out of my blog and nothing could get me in again and now i don’t know how to get back all the custom CSS changes I had made.

I just discovered they are stored in databases. Where exactly should I look for the custom CSS?

Thank you guys.