Om Swami
Why does my mind keep worrying about small things, and what can I do about it?
Take up something bigger than small worries
The human brain is designed to worry, so it is not possible to be free of worry till your last breath. You can either worry about many little things or take up something big, and nature gives power to those who take on bigger responsibility.
Till your last breath, it is not possible to not worry about things, because the human brain is designed to worry. That is its evolutionary basis.