Plenty of great comments here. I think a lot of them can be summarized by "getting out of your comfort zone". This doesn't mean that you have to do something you don't really feel like; it means doing something you're not used to. This can be as little as swapping to a different playlist/radio channel on Spotify, or as big as emigration, but my guess is that you're somewhere in between.

If these things don't help, talk to others. Maybe you have a colleague you can confide in. This is something that has helped me, because generally when you get into such droughts, it gets noticed by others, and if you don't talk about you seem like someone who doesn't care. This can create a really bad vibe, and put you into a vicious circle where you try to hide your inactivity/lack-of-inspiration, causing your colleagues/superiors to become suspicious, which in turn will make you feel worse about not feeling good.

So I'd say, talk, and try and evoke change.