Put everything on your calendar even personal meetings. Keep a separate to do list, prioritise urgent & important tasks. If you are firefighting all the time then there is something wrong.
Have standing meetings - If others don't stand, you still can, it will push you to be brief. Decline meetings which are waste of your time. Say "Sorry I may not be able to add much value to this meeting"
Pick your tea/coffee & have it on your desk
Put your phone on silent,check it only 3 times a day.
Sit in a meeting room if there is too much distraction on your desk
Keep your lunch break for 10 mins followed by a 5 min brisk walk after that. Will give you energy for the day.
Dont bring work home, ensure you finish it at office, dont work on weekends.
Excuse yourself from all gossip. If people are wasting your time excuse yourself politely.
Come to work early, finish all your pending work. I used to work from 8am to 4.30 pm, did it for 9 yrs. So it is possible.