“You must set your hands to tasks which you can finish or at least hope to finish, and avoid those which get bigger as you proceed and do not cease where you had intended.” -Seneca, On The Shortness Of Life
“If the first thing you do in the morning is to eat the frog, then you can continue your day with the satisfaction of knowing that this is probably the worst thing that will happen to you all day”. -Mark Twain
Of all the tasks on your to-do list, what can you complete today, tomorrow, this week? Start with those. Finish them off. You’ll be glad you did.
And for those other longer tasks/projects, ensure that you’ve given yourself a deadline for completion. (Remember your trusty ally, the work plan.) Otherwise, they wont get done. Or worse, they’ll grow into new, ongoing projects that never end. And your level of anxiety will grow commensurate with them.