taking on a long to-do list may only make you feel overwhelmed to the point that you procrastinate & get little to nothing done. make a realistic list & do the hardest things first.
multi-tasking sounds like a great idea, but it only divides your attention & nothing gets 100% of your effort. get one thing done at a time & then move on to the next.
a list of tasks & even a schedule breakdown will keep you organized & less frazzled about what to do next. this can help you be more productive & actually get those things done.
consider putting your phone in another room or somewhere out of sight if you find you're constantly checking it. if you're someone who needs background noise, consider music instead of TV.
once you've figured out what you have to get done, just start! you lose precious time thinking about all you have to do. before you know it, the day is done & you have little to show for it.