Lady Gaga’s former DJ, Brendan Sullivan, has sold his memoir, “Texts, Drugs & Rock ’n’ Roll,” to HarperCollins imprint It Books. Sullivan was an up-and-coming Lower East Side DJ when he met Gaga, then a struggling performer, in 2006. The book, out next spring, is described as “a literary memoir about love and heartbreak in the downtown New York music scene during the rise of Lady Gaga.” But it’s more inspirational than exposé. “My book will include six or seven people who either want to be Gaga or want what Gaga did,” Sullivan told us. “Fashion designers, young chefs, kids who are bartending on the weekends to make their dreams come true. The book is about what it’s like when you are in that position.” Sullivan penned a profile of Gaga last year for Esquire in which he reflected on how the pair used to “sit on the floor of [her] bare Lower East Side apartment, drinking wine from pint glasses. I would read drafts of my novel to her while she lay on the floor, head in my lap.”