I'm really sorry to hear that Cell : / . I would literally die inside if someone made off with my cards... easily worth around $1500-2k for everything I've got... my commander deck alone (which is my pride and joy) is worth about 300 dollars x_x
I do know the feeling though... when I was in 5th grade someone stole all my Yu-Gi-Oh cards... everything I owned... which compared to my magic stuff was nothing, but I still had quite a collection... I eventually got everything I lost back and more. I re bought starter decks and traded my way back to where I was... the only things I never got back were my soldier from another world card, and the "masked beast" card I re acquired was in Japanese whereas my original was in English but hey, close enough... My advice is to never give up! keep collecting and you'll get back to where you were. That... and find a better place to keep your cards lol. More specifically... don't leave your backpack halfway across the playground while you go play handball for 3 hours after school... funny thing is my game boy advance and all my pokemon games were in the very next pocket... which they didnt take... weird.