(in) up to (one's) eye(ball)s
Extremely busy; deeply involved or engrossed (in or with something). I'd love to come for a pint, but I'm in up to my eyeballs with work for my class on Monday. John has been up to his eyes with the kids lately.
up to your eyes
If you are up to your eyes in work or in an unpleasant situation, you are very busy with it or are deeply involved in it. I'm afraid I'll be late getting back. I'm up to my eyes in work. He's up to his eyes preparing for the trip. By this time Walker was up to his eyes in debt.