Maybe don't set yourself a "project" (quotes intentional). The idea of a "project" implies busy-work. Do something completely out of left-field. For instance

Maybe don't set yourself a "project" (quotes intentional). The idea of a "project" implies busy-work. Do something completely out of left-field. For instance, learn APL. It's like reading a Jorge Luis Borges short story. Why? Why not. Rinse. Repeat. Relish in the non-projectness of it. After a while, joy might come back.