To prevent your burnout you need to limit the amount of time you spend doing any activity.
Many people think that by working more they advance more but it has the opposite effect. You need breaks every 45 minutes. And studies show that people are way more efficient working 4 days a week instead of 5 or more.
Now you did mention a burnout. If what you are going through is not a burnout but something similar/something else. Then ignore my post. At any rate if it is a burnout do consider taking those breaks to clear your mind.