I've found that whenever I hit a point where I can't come up with any ideas I have to shake myself out of it somehow and that's typically by doing something very jarring. A few months ago I got into painting some lil wooden signs and began to connect the dots with how my style of design composition carries across mediums , which was really encouraging all in all.
If you have any interest in photography I'd say to just go on a few walks and focus only on the camera (this is difficult but doable regardless if your only available camera is your phone). That's my usual short-term solution, gets the mind going.