Mélusine: Lovecraft wrote short stories, novels/novellas, at least one verse-play (The Tomb), and scads and scads of poetry, much of it very good. I used to own a volume of his verse, can't remember the title, was it 'Fungi From Yuggoth'?
Another author to avoid at bedtime, though his work is brilliant: William Hope Hodgson, especially 'The House on the Borderland', a surprisingly modern horror/fantasy novel about an old house built around a dimensional portal. Both Lovecraft and Pratchett cited Hodgson as a seminal influence on their own writing, and a young Alfred Hitchcock was inspired to make the film 'In the Doldrums' by one of the short stories in Hodgson's 'The Boats of the Glen Carrig'.