find out why you can not concentrate on your job. You're too tired? go to sleep earlier in the evening
If you are a consultant or running your own business and you can not find a way to actually force yourself to do your work, then consider the fact that you might not be cut out for indenpendancy. Nothing to be ashamed about, and good of you to try it, but being an independant worker means much MORE work and much stronger self-discipline than being a salary man. Try to get a job which pleases you with a fix monthly income and paid vacation. You will be a lot happier.
tl;dr: find out why you can not concentrate on your work, act to fix the problem. Do not drop some aderall, as they will NOT make you happier, just more "productive".
now, dear AC, your turn
you mean the correct way to go offline while being online
The mind boggles.
Always draw your curves, then plot your reading.