请问英语语法高手进,谢谢!I must have soundde very proud of myself after

请问英语语法高手进,谢谢!
I must have soundde very proud of myself after the quiz,saying how easy it was and how I was sure to get a good grade.
请问老师这一句话saying how easy it was and how I was sure to get a good grade.在句子中做什么成分?是状语吗?请问是什么状语? 表达了什么含义?请详细解释.
请一定要有把握的回答,谢谢!