When someone is in debt

When someone is in debt
I’m in the red.
red = red ink = indebtedness
She’s in over her head (in debt). (idiomatic)
I’m up to my ears in debt. (idiomatic)
Bill’s writing rubber checks.
a rubber check =a bad check (that bounces back from the bank because there is no money to pay it)
I’m borrowing from Peter to pay Paul .(idiomatic)
I’m robbing Peter to pay Paul. (idiomatic)