The answer to that is you need hobbies and you must find time for hobbies. Why? Hobbies can lead to book ideas. For example my hobby of baking gluten-free lead to my gluten-free bakery mystery series. Another writer I know began to make her own soaps and this helped round out her historical romances.
The point being that yes, we are always told, get your butt in your chair and write. But without doing more than that the writing falls flat. The hobby you choose doesn't matter. It could be fixing scales, hiking, photography, playing in a small town band, weaving, painting, gardening. Anything to get you out of the story doing something where you have permission to do it badly. I mean, it's a hobby, right? So who cares if the scarf you attempted to knit turns out to be a pot holder? Hobbies free up the creative mind. They allow you to relax and let your muse in without the pressure of performance.
Give yourself permission to add a new hobby to your life and I am betting you will find that your writing is better for it.
If you could do anything, what hobby would you take up? I'm off to make triple berry jam. Cheers~