It seems a small step, but it is a huge deal, I finally did it! My first day without distractions. Because my study started yesterday, I have quite a lot to do. That helps a great deal, as I am busy with studying, so there has not really been a moment I was tempted to watch Youtube (yet).
There are 3 large changes I made compared to my previous attempts.
1: My brother checks in with me regularly
2: I imposed a new rule: I keep my phone downstairs. When I am in my working room, there is nothing else to do than just work, so that also does help.
3: I made a planning. There is so much to do, and by dividing it in small parts with a planning, is is clear what I can do, and less intimidating.