Days doing nothing are the default! There's nothing to be ashamed about. I wish someone had told me this when I was at my worst, but it's absolutely fine to while away a day, a week, a month doing nothing in particular.
The only thing you need to look out for is a little glimmer of excitement. For me, it was a short story I happened upon. The themes and characters had nothing to do with me or my situation, but as I read I discovered that I wanted more, and once I finished I researched the author and their other pieces. After that, the snowball was in motion. It's the same principle behind the self-motivation technique where you take a task you don't want to do, tell yourself you'll only do it for a few minutes, and before you know it, thirty minutes have passed and you're in the swing of things!