i use "Block the youtube feed" extention on my browser, it helps me a lot.
2) AFTER you block your youtube feed you will have a need to direct this energy elsewhere, generally it will be something negative again, like video game marathons, porn, or etc. I had the same issue,
3) but the process goes like this, you block your youtube news feed, then you start directing that energy to mething negative, then find a way to block that again, after youtube addiction i directed my energy into video games so then i just sold my graphics card, but then the cycle stopped and i directed this energy into productivity
this technique is called a "path of least resistance" - when you finally direct this energy twards something positive.
but based on what you said, i think it would be best for you to take a separate course on self-discipline,
and i recommend you to search on youtube 'path of least resistance' it worked for me and i hope it will work for you too.
cheers!