Environment plays a huge role in keeping your focus maintained. Your personal work environment plays a large role in your ability to concentrate. The more comfortable and welcoming your environment is, the easier it will likely be for you to stay there and focus. If there are any issues related to work, family matters, financial crisis, etc get resolved them as soon as possible. Probably one of them might be the reasons for you inability to focus on some other important work. Find out the reasons for the restlessness and try to relax by practicing deep breathing exercises. If meditation is confusing for you, get yourself a trainer who can teach you the actual and correct method of its application. In case that is not possible, find a comfortable place, relax by stretching yourself for few minutes, close your eyes and imagine all the good memories with your loved ones and feel happy sensing gratitude towards whatever you have. Once you attain the level of satisfaction in at least 3 areas out of 6, you will be able to increase your concentration levels too.