If you are burned out, it may very well be that you will miss that 'hard deadline'. However, very few deadlines in life are really 'hard' (as in you will lose your life if you don't meet the deadline.) Talk to the folks who have set the deadline to see if it can be rescheduled. If they cannot or will not reschedule your deadlines, then resign yourself to the consequences of the missed deadline and start thinking of your life beyond the deadline. If it is some sort of application deadline, remember these sorts of deadlines are artificial. You can always apply the next round. Or a different opportunity will arise. All the best. Don't make burnout worse by stressing about deadlines. If missing the deadline isn't going to result in your death or the death of a loved one, it's not a final deadline.