Taking a break needs lots of work. In today's life, it's hard to take a break and relax. You will find many people who don't take any breaks. One of the reasons is they are busy but another reason is they feel guilty for not working.
Work doesn't own us. Even if you are self-employed, do take breaks. Don't make yourself constantly trapped by different works. Have the freedom to accept that you are not feeling okay to do that work today. It's perfectly okay if you are feeling less motivated somedays.
Putting ourselves under pressure to do better round the clock is not a healthy practice. Work-related stress is the underlying cause of so many health problems and long-term mental issues. Also, it relates to our relationship problems. Having a good family life and connecting with life is more important than our job. So reconsider taking a break.
We need this power of choice sometimes to find ourselves, to reset our thoughts. Who says, you need to be productive every time? There's no gain to work or think about work round the clock. Give yourself a rest, even if it's for only one day. Taking a break can actually make us more productive. Don't think you are useless. Say to yourself that you are gaining energy and will do much better from next.
Do all those things you love to do during break time. Enjoy your time and give your mind time to heal. Don't deal with any kind of work-related thing, even if it's just a mail. Say to yourself that you deserve it. Don't think about the financial benefits, think about what enjoyment you can get by taking a little break from everything. You will feel totally refreshed if you can do that.
I hope it's gonna help in many ways to improve your personal as well as work life.