My advice would be to give the Pomodoro technique a try. http://en.wikipedia.org/wiki/Pomodoro_Technique
Divide your working time into 25-minute intervals, with a 5-minute rest in between to recharge your focus.
It helps me stay concentrated and prevent procrastination.
If it is your own mind distracting you, then give yourself 10 minutes to do a task that are avoiding, and reward yourself afterwards. The reward should be small, but something you only do after you've finished the task.
If it is what others are saying that distracts you, then go back to the headphones and this time listen to Brown Noise loud enough that it wipes out what people are saying around you.
If it is email/chat/socials that are distracting you, then close all programs except for those that you need to do your job. If you have to have email open, set email rules to pull out the emails important for your job, and store the non-critical emails in a separate location so you don't worry about them.
I personally find that headphones help a lot, but for me I must listen to either Brown Noise (or white, or blue, or whatever is best for you) sounds, or listen to music that has no words and has no beat. Words in music distract me, and any beat in music also distracts. I've also found if I can't understand the language that singers are singing, that is less distracting, so Benedictine Monks is fine.
Look for that thing that you can dive into. Then block out the other things. Noise cancelling headphones, blocked out calendar, phone on silent, meal prep, wfh. Treat your time and attention as a limit and precious resource. Agency is a wonderful thing.
you may find longer lasting results cutting out bad habits, bad people, bad food, bad information, etc.
One approach to overcome this is to try and partition the task into very small portions that you can do - that way you can make progress without being overwhelmed by the task.