Do you consider yourself a "real" writer? Many writers feel they haven't accomplished anything until they've written a book, or landed on the best seller list. Unfortunately, this is reinforced by people who belittle writers who concentrate on articles, essays, short stories, journals, poetry, etc.
The fact is, if you are serious about writing, you are a real writer. Bottom line, real writers write. If you set aside a certain amount of time each day or each week to put yourself in a chair and concentrate on writing, you should call yourself a writer. If someone asks what you do, tell them you are a writer. Don't feel you are anything less, just because you haven't written a book.
When my daughter was younger, she told me I wasn't a "real" writer because I hadn't written a book. No matter how many published magazine articles and short stories I showed her, in her eyes, I wasn't a writer. Of course, she was a child at the time and no longer believes that. Unfortunately, there are adults who think that way and may push those negative thoughts at you, undermining your confidence and belief in yourself. Don't feel threatened by other people's expectations. Simply, keep away from those people. If you are serious about your craft, you are a real writer.
People say they play tennis even though they're not professionals. People say they play the piano, even though they only play for their own enjoyment. If you want your writing to be a business, then treat it as a business. If you write because you love it and don't care about making money, then enjoy it. But whichever route you choose, if you treat your writing seriously, be proud to call yourself a real writer.