"You're the one to blame." "This is all becuase of you." But I don't think it's in a serious manner. 쟈기(자기) means sweetheart or honey. 땜시 is kind of a dialect for 때문에. So if I rewrite this into standard Korean, 이게 다 자기 때문이야. This sentence sounds like a cute complaint to me, though. :)