Little wins.  Start small and every little task gives a bit of a dopamine hit.  Don't look at a task in its entirety, little steps at a time. Timer, work for five minutes, then take a break for one.  Then work for another five minutes etc.  I get bored trying to complete a task to entirety so I tend to jump from one thing to another.  Stuff gets done.  Not ideal but brain is so burnt out it's a wonder anything gets done.  Start small and chip away.  If you need a break, take it.  Tackle what you think you can manage.  Write down each thing you manage.  Gives a bit of a boost when you see it down on paper.  Have a treat, just something small to look forward to, for when you've tackled something or worked throughout the day on something. All the best.