This is a book to get lost in. It’s a memoir in which Luke Turner, best known as co-founder of the independent music website the Quietus, tries to explain – to himself as much as to us – how, over many years, he has resisted but also honoured his bisexuality. It’s an account of falling out of love with London and seeking both solace and newness in nature. It’s a social history of Epping Forest, a piece of woodland that, straddling London and Essex, is also bi. A disturbing trauma narrative, it’s also a work of delightfully low, pants-dropping comedy, and a learned meditation, influenced by 17th-century Italian philosopher Giambattista Vico, on the nature of knowledge.

The book begins with Turner splitting up with his long-term girlfriend even though, he insists, he still loved her. Something was troubling him. It was the same thing that was becoming a compulsion: a desire “to feel the naked press of a man on top of me”. Over the next few months he acts on that desire, and then some. He also sleeps with women – not a few of them. He’s hungry, confused, sometimes reckless. Unmoored, he moves around the fringes of London, kipping in friends’ flats and attics, and spending as much time as possible in Epping Forest. He hopes that nature will offer a cure, some clarity.

Forests have long been seen as shelters for outlaws – and for outlaw sexuality. Some locals refer to Epping Forest as “Effing Forest”. Pollarding has transformed and even sexualised the trees themselves so that, according to Turner, they resemble “cows’ udders, a pair of buttocks climbing into a hollow, old men’s balls, a phallus between thighs, great, heavy, warty growths, welts like parted vulva”.

Turner marries Joe Orton and Michel Foucault in his descriptions of how, over the centuries, men have been forced “by law and religious prejudice into twilighting their sexuality to find a knee-trembler under a hornbeam”. They use off-paths and low branch overhangs to create “a private network, beyond cartography, beyond nature”. Discarded tissues and condoms become “territorial markers of a queer autonomous zone where heterosexuals might be advised not to tread”. But this is no sylvan utopia; having asked a forest keeper why so many fires have been blazing in parts of its grassland, Turner is told: “It’s people trying to burn out the gays.”

Turner is not ashamed of being bisexual. He says he struggles against “the binary rules of heteronormative love”. Why then does he feel so messed up? He ponders his upbringing and evokes an adolescence many readers will recognise: the fear of getting an erection in the changing room showers, the glee at finding a sports holdall full of copies of Club International, the silent drama of giving a classmate (whom he later dubs “Tippex Boy”) a hand job under the desk during a chemistry lesson, the struggle to make sense of our shifting, seemingly aberrant desires.

Art can be a lifeline at these times. It can name our dilemmas, legitimise our weird feelings. Turner found solace and possibilities in Withnail and I. The band Suede inspired him to wear women’s blouses and dye his hair red. Derek Jarman became “a mythic figure in my imagination, an alchemist who used his genius behind the camera to turn the moral opprobrium of society, the dirt of shame, into a seething power; a counterattack.”

Turner’s sexual turmoil was intensified by the fact that his parents were not only practising, but also preaching, Christians. His mother grew up in a fundamentalist sect that forbade most forms of 20th‑century mass culture, and the self-lacerating language of guilt and shame and unworthiness comes easily to him. Yet he respects their Methodism, is introduced to a lineage of English radicalism (Gerrard Winstanley, the Levellers) through it, and draws on its heightened ways of seeing as he immerses himself in the life of the forest and the altered states of consciousness it engenders. For him, forests, though often portrayed by theologians as pagan or Dionysian, are churches without walls, fecund in spirituality.

Out of the Woods (parts of it first appeared on the Caught by the River website, which has become a reliable treasure trove of contemporary natural history) reads both like a seance and an act of exorcism, a necessary purging. Will Ashon’s Strange Labyrinth (2017), also about Epping Forest, devoted chapters to the anarcho-punk bank Crass, whose members Penny Rimbaud and Gee Vaucher have long maintained an open house there. Turner’s reference points are more eldritch: English occultist and draughtsman Austin Osman Spare, the band Coil, whose music he describes as “narcotic and queer; it blurs the boundaries between our expectations of sonic urbanism and the pastoral psychedelic”.

At times, as he chafes against his background – its emphasis on sport, hearty masculinity, middle-Englishness (he admits to having campaigned for Tory MP Peter Lilley at a school election) – he recalls Stephen, the vicar’s son in David Rudkin’s visionary drama Penda’s Fen (1974) who discovers that he is “nothing pure! My sex is mixed. I am woman and man! I am mud and flame!” Like Penda’s Fen, Out of the Woods is animated by deep trauma: Turner’s confusion and shame about how, as a teenager, he was drawn to the public toilets in his home town and had oral sex with someone he guesses was five times his age. Was this abuse? If so, he wonders, what later drew him back to those places?

Turner’s memoir succeeds at many levels. It explores the kinds of questions about identity and interconnectedness that academics such as Eduardo Kohn (how do forests think?) and Catriona Sandilands (are plants queer?) have been asking in recent years. It does so without jargon and without self-absorption (it’s peopled by sketches of outsider artists and eccentric forest dwellers). It offers no fake epiphanies or grand statements. But, as all gastroenterologists know, it suggests it would be a grave error to think of forests as external to us. We carry the forest with us, inside us. We are the forest.

• Out of the Woods by Luke Turner is published by Weidenfeld & Nicolson (RRP £16.99). To order a copy for £12.99, go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min. p&p of £1.99.