The speaker says she has committed herself fully to a new love: her life, her love, "and all, and all." The repetition sounds like she is trying to convince herself it's true. But the second half of the stanza admits the old love hasn't let go. In dreams, the past hovers and calls to her.
The second stanza makes this feel eerily physical. She jolts awake with a shiver, yet she still feels a kiss burning on her breast. Beside her bed waits a "ghostly giver," someone she can't see but is sure is there. The poem doesn't say whether this earlier lover is dead or simply gone, so the "ghostly" quality could be literal or only a way of describing memory.
The mood is uneasy and haunted, but also tender. The speaker seems loyal to her present choice, yet her dreams show that her feelings aren't as settled as her promises. The short, tight lines make the memory feel hard to escape.