There is a Sanskrit word, ekāgratā, that means one-pointedness. The whole mind resting on a single thing, the way a magnifying glass gathers sunlight until it can actually burn. The yogis treated that kind of focus as something close to sacred.
Most of our days look nothing like it. A dozen tabs, a couple of chats, a phone lighting up every few minutes. Each little switch feels like progress, but it mostly isn't. After an interruption it can take you several minutes to find your way back into what you were doing, and most of us interrupt ourselves long before anyone else gets the chance.
The fix is boring and it works. Pick one thing. Close everything else. Stay with it until it is genuinely finished, or until you have genuinely decided to stop. That is the whole method.
What you pay attention to is, more or less, what your life ends up being made of.
Try this: Tomorrow, choose the one task that matters most. Set a timer for 25 minutes, leave your phone in another room, and do only that until it goes off.