I've often heard that if you want to be an author, you need to treat writing as a job. I know that many writers push themselves, feeling that if they're not writing they're not making progress, not getting paid. And to a certain extent that true. We do need to take writing serious if we want to do this professionally. We can't treat it like a hobby.
However, professional doesn't mean 24/7 in most cases. The Engineer has weekends off work. When he comes home he doesn't agonize over blueprints and obsess over airplane parts. Generally, that is. Farmers let fields lie fallow sometimes so it can regain nutrients and produce better crops.
As writers, we need to take time off. We need to let our minds lie fallow for a bit. And we need to stop beating ourselves up about it. If we push too hard, we face burnout. Just like anyone in any profession. Take care of yourselves, and remember that you need time off work every now and again.