Attention disorder and always racing after the new shiny project is a common problem amongst developers. I myself used to start new projects every few weeks and abandon them as soon as I got excited by a new idea.
Learning to force myself to focus on one thing until it is done has changed the impact of my work dramatically. It is not easy to stay the course, but well worth it. The small spike of adrenaline provided by starting a new project is less rewarding than seeing a project flourish.