If you don't have time to read, you don't have time to write. A master storyteller, last name of King, said that. He should know a thing or two about writing. I've had wonderful ideas pop into my head just from reading other authors' works. A different perspective, a fresh take on something is often all you need to get back on track. This can also come from watching a movie. Listen closely to the dialogue. Pay attention to the camera angles, lighting, POV. Understand how a movie scene is shown. Use some of these tactics. If you're still not feeling it, go outside. Fresh air will do you good. Go for a walk. Sit on the porch and listen to the birds. Don't think. Let your mind relax. You are creative. Something will stir you. Before long, words will flow again.
It doesn't matter how many. I've never been concerned with a daily word count. (Unless a deadline is looming.) The only words that count are those that are commercial. Everything else is just fluff. People don't have time for unnecessary words. Eliminate them and keep your story tight. If I only write 100 words, but they are all good, then it's been a good day.
Not in the mood to write? Do it anyway. Make progress, not excuses. Tomorrow, 5,000 words may find their way onto the page.