What is the author's tone in The Complete Poems by Anne Sexton?

The poem, Live or Die, concerns itself with a particular period of time in the author's life, one in which her swings of manic depression are followed. In the preface, Sexton reveals that the poems appear in the order in which they were written, between 1962-1966, hinting that this was a turbulent time in her life, apologizing for their melancholy tone.