When He's the focus, worry subsides. When the problem is the focus, worrying persists. Don't worry about anything. Pray about everything. And His peace which surpasses all understanding will guard your heart and mind.
Create first a good habit, next push on to create a good lifestyle. I do not know how accurate 21 days and 90 days are in terms of creating a habit and lifestyle respectively. But I do agre. (Nice Try Health Fitness)