Lost memory stick

I lost my memory stick outside coppers on hardcore street, Dublin or in a taxi! It was in my purse upon leaving the house to go out. Its a 'median' silver one with no lid on it, has a huge amount of college work on it both old and new with essays and work due on it. Unfortunately I have no back up. Reward upon return. If one opens it on the computer they will see folders with camp america, causes of civil war etc.