Nice article. I prefer the word striving to struggling though. I know you used both, but striving I think is more appropriate.
Struggling can imply lack of mastery of a challenge.
Striving implies attempts at moving forward no matter whether you are a beginner, just about to gain mastery, or already gained mastery, yet continuing to seek improvement.
Happiness is what I refer to as (just a rephrasing of your message in my own words):
“discontented contentment” — Contentment that always strives for improvement not because of what the neighbors have, but based on morally upright professional or spiritual goals, values, virtues, objectives, and purpose that are self imposed.