I'm starved very much now because I have had nothing at all

starved 是adj. 饥饿的 这里不是被动语态, 是一个形容词
have nothing 是 have nothing to eat 缩写
这里是一个现在完成时的句式, 用现在完成时表示对现在的影响, 我今天一天都没吃东西,所以我现在饿极了.
have done sth
have had nothing 过去完成时