What does "你什么都不是" mean? Literal translation:

你 - You
什么 - what / who / something / anything
都 - entire / all
不是 - blame

My guess - It's all your fault?
Literally: you are nothing at all, usually used in a disparaging way from what I can gather.  It follows the common pattern of Sub+什么都不+Verb, meaning that the subject verbs nothing at all.  Ex: 我什么都不知道 = I don't know anything.