The quote “the morn… / Walks o’er the few of yon high eastern hill” is an example of personification. Personification is a form of figurative language in which an abiotic factor is given human qualities.
The quote “if, like a crab, you could go backward” is a simile. A simile is a comparison or direct approach of something using the words “like” or “as.”
The quote “A dream itself is but a shadow” is a metaphor. A metaphor is an indirect comparison between two factors that doesn’t require the words “like” or “as.”
The quote “But break, my heart” is an apostrophe. An apostrophe (in literature) is the addressing of someone or something who isn’t literally there; it’s similar to personification, except the person is talking to the inanimate object.