You're probably used to going nonstop and never taking breaks. (I know firsthand — I was answering emails on Christmas Eve!) If you have trouble setting aside time every day to do something for yourself, then try to make 2019 the year when you give yourself a day or two off every month. You can work all day and night the rest of the month, but allowing yourself to have a "me day" will give you a break to look forward to, and will work wonders for your productivity.