Close your eyes, put your finger on a random place on a world map, and then make plans to visit there as soon as you can.
Kor
That was going to be my suggestion, more or less: travel. Even very occasionally.
There's no downside. If you're as content as you think, you'll likely find both that the places you visit will bring you joy and that on return you'll find yourself even happier with the place you live now.