1
general::
Phrase(s): *up to one’s neck (in something) [and] *up to one’s ears (in something); *up to one’s eyeballs (in something)
having a lot of something; Fig. very much involved in something; immersed in something. (*Typically: be ~; get ~.) • I can’t come to the meeting. I’m up to my neck in these reports. • Mary is up to her ears in her work. • I am up to my eyeballs in things to do! I can’t do any more!
McGrawhill's American Idioms And Phrasal Verbs