Extremely busy?
I am up to my eyes in work
This is an area or topic that I don't know much about
I am out of my depth
Extremely happy
I am over the moon
Just in time
In the nick of time
Something we are familiar with; a place we know well
Like the back of my hand
To move connections for some
To pull a few strings
To do the same thing that somebody did previously
To follow in someone's footsteps
