I think that the figurative language used in this poetry is good. Firstly, I would like to say about the figurative languages he used, like O God. This is a hyperbole statement. In a way, the author has described his feelings in an exaggerated manner. He describes that he feels sad that his hopes has flown away.
I also think that he used metaphors, like "I stand amid the roar of a surf-tormented shore". The author also describes his feelings that he feels like shouting to release his emotions, grief within him to feel better.
Lastly, I think that the symbolism he used is the sand. He feels that he is like the sand in the pitiless wave. That the sand crept through his hands into the sea and he cant even save one in the pitiless sea. I think thaat the author feels just like the sand.