Money Lost and Replacement

I have $42 that I left in my wallet, which I left in my bag, which I left in my household for weeks. Today I checked my wallet only to discover $41 out of the $42 is missing, leaving me with only $1. My reaction was bizzare. I am a 14 year old with no allowance and no income. This is money purely earned from over the year from what I already had before.

I was supposed to make future purchases, and even planned with a friend to haul future products to my house that would be purchased with MY money, only for everything to go on freeze. What am I supposed to do? How will I cough up the money? How will I get the $42 back?