Purpose can begin with asking who benefits if you become better.

Self-improvement can circle inward until it becomes its own subject. Asking who benefits when you get better breaks that circle immediately, because it forces the development to point at something. It also usually clarifies which improvements actually matter and which are decoration.

Name one specific person or group who would be better off if you were more capable. Then let that determine what you work on. The question is small and it reorganises a lot.