There are two costs involved in performing any task:
- The work: the time and effort it takes to complete.
- The reaction: the mental and emotional energy surrounding it.
To be efficient at doing what you want to do, you have to ensure that the second cost does not also involve significant time and effort.
Spend significant time fretting, worrying, complaining, and not doing, and you have just massively increased the total cost of that task.
If your half-hour of homework comes with an additional half-hour of complaining about it, then it now costs you an hour to complete your homework. Guess what? That leads to more frustration, further increasing the #2 cost, and leading to a vicious circle.
If you can set aside #2 until you have spent time on #1, you will find that your negative emotional response will be minimized. The reaction will cost less if you can just focus on completing the work quickly and effectively.
In other words – quit complaining and do the work.