Organising can improve your wellbeing. Having good mental health can improve your wellbeing. The practices associated with improving your personal organisation over-lap with many practices for improving your mental health.
By starting the process of developing healthy routines and decluttering what is no longer needed, you can become more efficient. As you increase your efficiency you may find your time management improves and in turn you release even more possessions or commitments that you feel weigh you down.
By adopting a positive, growth mindset and a practice of self-care you can improve your mental health. By seeking out help when you need it and taking care of your physical health you give yourself the best possible chance of achieving optimal health.
I strongly believe that by investing time and energy in improving your personal organisation you can reduce levels of stress and increase your wellbeing.