Burnout is typically caused by emotional and cognitive overload that causes a individual's capability to cope with the stress. 

Take a timeout, reconsider and remind yourself of your most dominate "Why" and what makes it matter so much. Why are you seeking the goal(s) that is driving your aspiration and your reason not to relent? 

Reassessing and reimagining your goal(s) will give you the opportunity to refresh your focus and intentions. The other thing to consider is that it's never too late to start again. Each day there is a new beginning; thus the sun will rise again. 

Remember, you're not starting from scratch, just from the point you realize it is necessary to shift and optimize!