Simple rule of mind.

First rule is the mind becomes negative when you face something more challenging than what you already know. this is useless voice. it kind of hinders, and makes you to move in different direction. learn to ignore.

The key is to not give up, tolerate and continue, this is the best mental training, giving up or switching task can only produce unproductive state of mind. If you completes the task, it gives a surge of energy afterward.

If task is way out of hand see how you can create the stair but don’t leave any task hanging. this creates the negative mind.