logically a family member found it. you might of taken it out of your purse briefly and forgot to put it back in. or it fell behind something [bed, desk, table]
spiritually i've heard a theory that your deity/deities might hide important things on you as a lesson [not maliciously, but just as a way to say 'hey! listen up!'] one time i offered some less than optimal fruit and the same day my favourite journalling pen went missing, only to appear in the exact spot where i always keep it once i apologised to my Goddess for the fruit. it could also be a way to tell you to take your nose out of the book and start doing. you say you feel lost without it, perhaps it's the Lord and Lady trying to tell you to take a deep breath and practice how you feel, not how the book says.