Rhymed AABB quatrains. For a poem so conceptual and hidden, the monosyllabic rhyme scheme (until the end) wants the reader to remember this poem, which, ironically, is against what the speaker wants. What the speaker wants is to be "forgotten" and become one with "oblivion."
A bit overblown? Not really, another way of looking at this poem is what the speaker thinks of death and of outside forces -- to me, this is more of a character piece than a poem that has high philosophical value.
The opening lines, "I hope when I am dead that I shall lie / In some deserted grave [....]" has a very strong sentiment to amplify the need for loneliness and the, "I cannot tell you why," adds a sense of mystery that the reader wants to uncover. However, the mystery doesn't do it for me as the next two lines reiterate this sentiment, "But I should like to sleep in some neglected spot . Unknown to every one, by every one forgot."
I'm not concerned why the speaker hates people, rather these lines, "And I should never hear the note of jealousy or hate, / The Tribute paid by passerby to tombs of state." Now, the jealousy and hate part is hyperbolic to put on all people, but this is what the speaker thinks people are. However, what the the speaker thinks of itself, "tombs of state." Someone worth a something on a state level. It's the idea of worth. For the speaker's worth is given tribute through jealousy or hate which she wants to shy away from, "To me would never penetrate the prayers and tears."
The idea of prayers and tears and tying them with jealousy and hate, and then tying that in with people is a long thread of reasoning. This is what the act of death feels like.
So for the speaker at the end, Oblivion, "the shroud and envelope of happiness" is an afterlife thought. The bliss is not something new.