It was--A--he said---A-----disappointed me.

这是一个强调句型,"it is/was。that。。。"是固定搭配,"what he said"是被强调部分,你可以发现去掉"it was that"后,句子仍然完整,这是强调句的一个特点。"what he said disappionted me"是主语从句,"what he said"做主语,主语从句"said"缺宾语用what补足