"If I had my druthers, I'd stay home from work today."
in over one's head: in a situation that is too much / too difficult for one to manage.
"Do you have time to help me? I thought I could do this myself,
but I'm afraid I'm in over my head. I just can't handle things alone."
inside out: with the inner part on the outside and the outer part on the inside.
"Why are you wearing your tee shirt inside out?"
in stock: in supply and available to buy / sell.
"I'm sorry, but we just sold our last pair of hiking boots. If you come back
at the end of the week, however, we should have some more in stock.
in the black: profitable; not showing a financial loss.
"What did you do to increase profit and eliminate losses?
We've been in the black for two months in a row."
in the red: unprofitable; showing a financial loss.
"We have to do something to increase profit and decrease losses.
We've been in the red for two months in a row."
in time: not late.
"I thought I was going to be late for my flight, but it was delayed, so I was still in time."