Ever since I learned the skill of being able to prioritise, life for me has become so much less overwhelming. To prioritise means to determine the order for dealing with a series of tasks according to their relative importance. To be a successful prioritiser means executing the tasks in that order.
I realise why a lot of autistic people may have trouble prioritising. The fundamental answer is that prioritising is a skill controlled by executive function, which is an area of difficulty in people who are autistic.