True, you can’t be writing ALL the time.
In fact, a good portion of your spare time will be spent finding inspiration, doing entirely something else.
Do whatever it is you want to do on your spare time- indulge yourself with a road trip, read a new book, or just spend some quality time with your loved ones.
A little self-indulgence is alright. Play if you have to. Meet your social needs. And yes, you may want to take a shower too.
Another tip: You may want to organize your notes. Be as obsessive-compulsive about it as you need to be. After all, you’d want to be able to take over where you last left off, even after taking a couple of oblivious days to recharge.
Here’s another: You also may want to keep yourself sharpened by writing something else. Have a go at short stories, or put new entries in your blogs, or maybe review other people’s works. This way you can satisfy your need to do something different, while honing your craft a the same time.