Pi Hole with my own blocklist. That is, I block all of my problem sites, then let someone else set my pihole password and then I delete my ssh key off the server.

Then on the phone, remove all apps that allows consumption (social media, games, readers, youtube, even the browser). Debloat it with adb too. Switch off all notification except for your main chat app (like whatsapp) and alarms. If still too distracting, set the screen to monochrome. Do not allow your phone to enter your bedroom & charge in another room.

Same with laptops/tv, keep them out of the bedroom.

For series, movies & games, have a set window per week/month to watch/play, do not endlessly play when Idle. Give your brain something intentional to do.

Avoid pornography as it can hook an adhd brain to the max and destroy your attention span.

Avoid caffeine if you can, drink more water, go bed earlier - it all adds up.

You basically have to change your relationship with the computers/internet and not allow yourself to consume/browse without intent or a clear goal. The internet is basically crack for our brains, so avoid it as much as possible.

Get some physical exercise and/or sunlight, once a day. Something as simple as stretching for 15 minutes makes a huge difference.

Remember that your brain WANTS stuff to do, it will generate an endless stream of crap to do if you don't learn to focus it. The internet is just the easiest way for it keep busy if you don't use it.