I used to flinch when I heard the word family. It conjured up vivid memories of rejection and humiliation and loss. I grew up in a curious kind of foster care. My wealthy Nigerian-born mother had advertised me in a magazine, made a private arrangement and sent me to be raised on a council estate by an elderly white woman in an all-white West Sussex town. The slightly eccentric silver-haired woman who raised me was more like a doting gran than a mum and I called her Nanny. I had love but I felt like an orphan. I'd never, as far as I knew, met my dad and feared he was dead. Then there was my mother. In 1981, bristling from having lost custody of me after being taken to family court by Nanny, I remember my mother saying, "You're dead to me." I was 10.
I grew up assuming it was me against the world. Other people had families – I just had a highly developed survival instinct. Nanny adored me and her grown-up daughter, Wendy, and son-in-law, Mick, loved me too. But Nanny had her own, white, grown-up children and Wendy and Mick were trying for their own baby.
As an adult, I came to dread that moment when people would ask, "So, where did you grow up? Where are you from?" On the rare occasions I ventured to explain the dynamics of my family history I'd regret it. The more detail I gave, the more emotionally drained I'd feel. I'd watch the listener's facial expressions slide from curious to confused to pitying. "It's complicated, isn't it?" I'd say, almost as an apology.
My family, my past, made as little sense to me as it did to others. I searched for answers for years but the more questions I asked, the more confusing the whole picture became. Even the circumstances of my birth are hard to fathom. My mother, according to her, had married a well-heeled Sierra Leonean in the early 1970s. This would have been my father. Oddly, despite having probed members of my mother's family about that time period, I haven't found a single person who attended the wedding. I've never even seen a wedding photograph.
My mother's plan, I suppose – she has never fully explained any of this – was that I'd leave Sussex and return to her in London, or to Nigeria, at some point. That's not the way it turned out. In 1981 I was made a ward of court with Nanny, now 67, as my legal guardian. Wendy and Mick had their own daughter and then they adopted a son, a gorgeous Asian baby boy. Wendy and Mick privately fostered African kids, too, but these kids would come and go, rarely staying more than a year. Even though I didn't want to return to my real mother, each time an African birth parent swept in and reclaimed their son or daughter I felt an enormous sense of rejection. Why them and not me?
Fast-forward to 1992. A tiny, beautiful black tot in a frilly dress skips along the pier. The little girl holds hands with two people – a middle-aged white woman in a long, fuzzy cardigan and a skinny black girl, dressed as if she's going to a rave. A fortysomething white man with shaggy hair and a slightly gruff voice looks from the black girl to the white woman who is his wife. "What on earth is your mum wearing?" he says to the little girl. "Which mum?" replies the little girl, looking from one woman to the other.
She has two mums. There's me, the giggly girl who is her real mum. Then there's the woman I've always secretly thought of as my own mum, Wendy. But Wendy is now, to all intents and purposes, my daughter Alice's mum too. My daughter's real dad was 17 when I got pregnant (I was 18) but both Alice and I think of Wendy's husband Mick as our dad.
A few months later, I travel to London, alone. I show up at my birth mother's home unannounced. I'm searching for something and I am not sure what. I've got it into my head that my mother will hug me, even invite me and Alice to live with her. I feel she will somehow teach me how to be a mother as I feel I'm failing at it. We sit in her living room in silence. My mother tells me I am too thin – I am. I'm bordering on anorexic. My life feels so out of control that refusing to eat is the only way I can feel in charge. I ask my mother to please give me some photos of the two of us, from my childhood – perhaps of her holding me as a newborn baby. No such photos exist, she says.
Maybe I want proof that I was once an important part of this woman's life. "I don't have any. I lost them all," my mother says. I look around the room and notice there are photos of my two half-brothers all over the wall, but none of me. I tell my mother she must have photos of me, my voice comes out almost as a scream, and she complains that I am trying to "rake up the past, yet again". She tells me she's tired and that I should leave so that I can get back to Sussex before the last trains leave.
After I've left, I look back up at my mother's window. She is standing there, looking down at me, with a look of utter loss and desolation. As if I am a ghost from her past. She gives me a sort of half-smile but looks like she is about to cry. I tell myself that my mother really loves me. That is why she looks so sad. She loves me and she fears it is too late to rewrite history and become my mother.
I go home to my daughter but I don't stay for good. Soon I'm a full-time student again. I win an academic prize, get good A-level results and suddenly I'm off to Oxford University.
Wendy will look after my daughter. It feels inevitable but I don't feel good about it. I'm not the only teenage girl on our estate to get pregnant, admit she's not capable of providing a good home and leave the baby with her parents. But society doesn't see Wendy and Mick as my parents, even though I do. To the outsider it looks like I'm abandoning my child to be raised, as I was, by "white people". I go to university, I do a postgraduate course in journalism, I become a journalist. I feel I've gone so far that I can't come back. When I do periodically come traipsing back, my daughter accepts me just like that, and still calls me Mum even though I'm not always there. Why can't I create for her the perfect family life I'd dreamed of myself as a child?
I continue with my search for my "real" family. I find my father's family. I learn that he was killed in the civil war in Sierra Leone in 1999 but the rest of his family is alive and living in America and England. I'm stunned by how functional and privileged they seem to be, like an African version of the Cosby Show family. But they don't explain why they didn't search for me.
In 2009, Nanny dies. I hold her pale, tiny hand on her deathbed. At the funeral, her coffin is tiny and I want to scream: "That's the woman who taught me to read. She's not allowed to die. She's my family." Instead I stand in repressed silence.
After Nanny is buried, Wendy and I suddenly open up. I ask why she agreed to look after Alice while I studied and continued to do so long after I'd finished. Her answer surprises me. I thought she'd say that at the time I was in no fit state to do a good job of mothering; that I was broke and emotionally unstable and confused. Instead she says that while she felt I could have made a go of it as mother, she'd felt that I was very bright; it was obvious to her that I should continue my education and Nanny wanted me to as well. So they decided to help me. It was as simple as that.
I feel a door opening. I've been an elusive presence throughout my daughter's childhood but motherhood doesn't end the second a child turns 18. I realise how much I've thrown away by focusing on loss: on the loss of my biological father and mother. On my fruitless quest to find a family who looked like me.
Unlike my own mother I'd been blessed with strong maternal feelings but I'd carried on as if I was in a coma, hearing my loved ones speak but unable to communicate with them. I had to let go of my obsession with what I didn't have and embrace what I did have, most importantly my daughter.
Since the day my mother told me she'd lost all my photos, I'd developed an aversion to childhood pictures. A few months after Nanny's funeral, I asked Wendy if she'd give me some photos of me as a child. She brought out an enormous box of pictures and as I picked through them I began to feel that familiar sense of dread. Wendy showed me a photo of me aged about three. In it, I've got solemn eyes and an unsmiling face. There was a turbulent time where my mother took me back, then returned me to Nanny. Along the way, I had been molested by a paedophile. I saw the ugliness of what had happened to me written all over my young face. Wendy pointed at my stroppy, sad face in the photo and said, "Look how beautiful you were."
Her face broke into a smile. She reached over and hugged me and said, "I'm so happy you're back. We all love you so much." After more than 30 years of searching, I had finally found my family.
Precious: A True Story by Precious Williams is published by Bloomsbury, £14.99. To order a copy for £14.49 with free UK p&p go to guardian.co.uk/bookshop or call 0330 333 6846