1. Youtube. I'm currently battling YouTube addiction as well, today is my first day without watching YT videos. For me it's really important to find some activity that will replace YT, and to do that activity everytime I have an urge to hop on YT again (currently it's practicing card magic).
I also know that I can't allow myself to open YT page in my browser, because that would mean I already lost.
2. Procrastination. I have been procrastinating my whole life (I'm 22 now). A book that really helped me was Atomic Habits. Power of Habit is also a great book, that explains why we keep doing things that we don't want to do and how to change that.
Good luck, and keep going 🙂.