Correct and smart decisions aren't possible without setting priorities, like which has to be taken first and which can be put off. It is how you have go about to avoid burnout.
Begin with your gut feeling and consider the factors like understanding your job description, the responsibilities of your boss and what he wants from you and how you can help him. Also keep in mind the company's vision and culture. For getting the right perspective, consult your boss, set the priorities and review them periodically.
Follow priorities
Mere setting priorities won't bring in results. It is good to make others know what is there on your plate so that it becomes easier to keep your action schedule manageable.
If a high priority task conflicts with another task, the best way to tackle the situation is to deviate from your first preference and think whether it is advisable to take up the new task and later on pick up the earlier one. You may not get clear cut directions as most bosses won't go into the details and as such it is your responsibility to decide.
What you would do when your boss says everything is priority. In that event, seek out another place to work and get out of it. That is the best possible solution to such a problem.
Extra help
Besides priority-setting, you can go for certain things that help you cope with the growing demands of work and finally avoid burnout.
The first thing you do is to seek extra help at work and home to meet a hectic schedule. You must learn to take regular breaks to invigorate yourself. Let your family and friends know that you are facing an extra-challenging work and you need help.
After the challenging work is over, do a postmortem. Find out whether you were expected to do the work on your own, whether you got good sleep, or whether you have to do anything else in a different way if you face such a situation again. Then make changes in work style and personal life.
That is how you can be on the track to your admin career growth.