You don't control your mind.
Most of the day, your mind is on autopilot, or worse yet, is being hijacked and controlled not by you, but by the many primitive subminds someplace inside your skull, lurking in your brain's subconsciousness.
These subminds include your insecurity submind, your envy submind, your worry submind, your machismo submind, your frustration submind, your anxiety submind, and your hedonism submind.
These subminds, not you, send you into episodes of frustr.