Do you want to be a writer, or are you a writer? The world is filled with wannabe's. I could fatten my bank account considerably if I had a quarter for every person who's told me, "I've always wanted to be a writer." People think of writing as a glory-filled, cushy career, and it is not. You must be willing to put in the time, the work, the energy it takes if you want to call yourself a writer.
Few people realize that there are many successful writers out there whose names you'll probably never know. They write ad copy, magazine articles, grant applications, technical manuals, brochures, and, often, their names are never published. The percentage of professional writers who get their names in print is small, and the percentage of those whose names are recognizable, is infinitesimal. If you're born to write, you'll write and write and write until you've honed your craft. Will you be successful? That depends on your definition of success? If success to you means financial wealth, don't count on it. However, if you're a writer worthy of the title, you'll achieve some measure of professional success and a great sense of accomplishment and fulfillment. If you're a writer, do it!