Fwiw, concentration can be improved with practice. It's like a muscle.
You could consider a mindfulness course maybe. There are some good free ones online that you could try out.
As a basic exercise though, try and sit ( or walk ) somewhere without distraction. No phone, no podcast, no music. Try to concentrate on the experience. What can you see, smell, feel etc.
Also, try reading a little, even if you don't want to. Books don't give the instant gratification of gaming, reels etc so we need to push past that discomfort in order to regain the habit. Set a timer for 10 mins to start, and see if you can read for that long.
It is very disheartening to make profound changes for the better and not feel the benefit. I hope that you feel better soon.