I Lost All of My Diamonds

I was playing on PE, and I decided to craft a diamond axe, as it is a pain to bring only three diamonds, I brought all 12 of my diamonds. I then crafted a pick on accident, and crafted a second, again on accident, at this point, I was extremely mad at myself. I thought maybe restarting the game will get my diamonds back, while I'm still in the crafting table, I come back, all of my diamonds are gone.