The speaker describes a dream in which she lies in a field of buttercups under a warm, golden sun. It feels so real that she believes she is awake. The sunlight makes her feel free, as if nothing could ever end and everything were just starting. She also recalls the comfort of someone's touch, which used to heal her, and the memory seems to return along with the warmth. The phrase "your touch" suggests she is thinking of a particular person, though the poem never says who.
Then the dream breaks. In the last lines she wakes into a world she calls loveless and brutal, and the sharp change in tone is the heart of the poem. The mood begins soft, bright and peaceful, then drops into disappointment and bitterness. The simple, plain language and the loose rhymes make the dream feel gentle, so the harsh ending hits harder. The poem is about longing for peace and tenderness, and how painful it is to lose them on waking.