If your brain expects a new hit every few minutes, long focus will feel weird at first.
That does not mean your attention is broken. It means your habits have been training the wrong mode, and that is something you can reverse.
You did not lose focus. You trained for interruption
Your brain has a focus mode and a wandering mode
Focus mode helps you work on one task.
Wandering mode helps you reflect, imagine, and plan. The problem is not switching. The problem is switching every few seconds.
Interruptions cost more than the interruption
A message does not only cost the time it takes to read.
You also pay the restart cost: remembering where you were and rebuilding momentum.
Interruption recovery can take minutes, not seconds.
Interruptions cost more than they look like
A single interruption is not just the second you spent checking it.
It is also the ramp back into thought. If you keep checking every few minutes, your brain keeps paying that restart cost and never really settles.
What you repeat gets easier
Shallow checking trains shallow checking.
Longer single-task work trains longer single-task work. Your brain keeps adapting to whatever pattern you feed it most often.
Focus usually comes in waves
Most people do not feel equally sharp all day.
There are better and worse windows. Put demanding work into your best window and use easier tasks when your system is clearly fading instead of trying to bully your way through the whole day at one level.
Try this
Take one real reset
When your head feels full, take 10 minutes with no phone and no inbox.
Walk, look outside, or sit somewhere quiet. The reset works because it stops asking your attention to fight.
Try this
Use a 5-minute on-ramp
Before the hard task, do 5 minutes of simple setup on the same project: outline, sort the files, highlight the brief, or write the first ugly sentence. A tiny real move beats waiting to feel completely ready.
Try this
Hide open loops
Close the tabs and apps that have nothing to do with the task in front of you. Leave one document, one browser window, or one notebook open if you can. The less unrelated stuff your eyes keep seeing, the easier it is to keep your mind pointed in one direction.
Try this
Reset like you mean it
If your head feels fried, take a 10 to 20 minute walk with no podcast and no inbox. A real reset works better than pretending you are still concentrating while secretly bouncing between five low-grade distractions.
Try this
Train range, not perfection
If 60 minutes feels impossible, start with 15. Phone in another room, one task only. Repeat until 15 feels normal, then move to 20 or 25. Build range instead of shaming yourself for not already having it.
Key idea
What to remember
Attention works better when you reduce switches, protect one real focus window, and use smaller clean intervals until your range improves. You are not trying to become intense all day. You are trying to spend more time settled on one thing.