up to your elbows in

up to (one's) elbows (in something)

Extremely busy (with something); deeply or overly involved (in something); possessing, filled up with, or overwhelmed by an excessive amount (of something). There's no way I can take a vacation right now, I'm up to my elbows in work at the moment! I only intended to be peripherally involved in David's business venture, but, before I knew it, I was in up to my elbows! Dana was worried she wouldn't find any work as an accountant working for herself, but she's up to her elbows in clients!
See also: elbow, up
Farlex Dictionary of Idioms.

up to your elbows in

1 with your hands plunged into something. 2 deeply involved in. informal
See also: elbow, up
Farlex Partner Idioms Dictionary
See also:
  • up to (one's) armpits (in something)
  • up to (one's) elbows (in something)
  • up to (one's) eyeballs (in something)
  • up to (one's) eyes (in something)
  • up to the eyeballs
  • up to the eyeballs (in something)
  • up to the eyes (in something)
  • up to your armpits
  • up to your eyes in
  • in control of