By the sounds of it, you just need to block certain places, like x, Reddit, YouTube/google, Facebook/IG, etc.

I run my own DNS server, but you could to the same with a blacklist on your router if it's a decent one. I've blocked all the social medias except for youtube (I don't do comments on there anyways). If a web search leads me to Reddit or something like that, I am looking for a solution to a particular problem, I'll use my mobile data briefly then go back to my wifi.