One thing I like about reading authors' diaries--maybe the main thing--is how they honestly reflect the difficulties, the ups and downs, of the writing life. There are days when everything clicks and the words flow. There are days when acceptances pop into the mailbox. But there are also many days of self-doubt, emptiness, stuck-ness. Days when a good idea just won't come, or an idea that seemed good the day before now looks pitiful.
It's reassuring to remember that's all part of the process. If it doesn't feel like magic and moonbeams every moment, that doesn't mean we're doing it wrong. Plenty of writers have gone before us, acknowledging that the path can be rocky. If we trip over the occasional rock or wander off into the nettles, at least we're in good company.