Vaughan's speaker is standing in places they love deeply, and it all feels almost too good to be true. The poem circles around one idea, repeating the phrase "walking in a dream" until the feeling becomes the whole point. The speaker even admits that no matter how they word it, the feeling stays the same.
The middle of the poem turns to a dream the speaker has had many times before, always cut short when morning arrives. The image of day gripping and ripping "the night to shreds" is harsh and a little violent, which shows how painful those wake-ups were. That makes the present moment matter more: this time, it is real.
Yet the ending doesn't settle into relief. Even while feeling it all, the speaker still can't quite believe it. The mood is wonder mixed with disbelief, a happiness so strong it seems unreal, and the closing repetition leaves us in that dazed, grateful state.