(use it in a sentence, leave it in a comment)
up to one’s eyeballs / up to one’s neck / up to one’s ears
deeply involved, or, in a bad situation because of having a huge amount of something
Filing my tax return is taking ages, I’m up to my eyeballs in receipts and invoices and bills.
She can’t come out tonight, she’s up to her neck in work and has to get it all done by morning, I think she’ll be doing an all-nighter!
The city council is up to its ears in debt.