One way to focus on one thing is to do a To-do list. It is a good way to get things out of your mind. It actually calms me down because I don’t have to remind myself all the time to do X or Y. If you never have done it, try it out!
The Distraction Stop Checklist will help you if you have no problems with anything else except the work you have to do.
You can download the High Res PDF file down below past the JPG picture. Print it out and put it somewhere at your place where you are working. Every time before you start you can use this checklist for a distraction-free work session.
Here is the JPG Picture. The bigger PDF File is down below.
The bigger version of this checklist
Download of the Distraction Stop Checklist PDF file: