My ADHD is not improving as i age :(

Hi,

I am coming here seeking advice. I am 21, studying and am currently doing an internship. But it's not going well. I am struggling so much with getting disctracted and watching youtube. Even though i often do want to do someting, i often don't do anything except watch youtube. When i do actually do something it's often not what i need to do. It's getting really tiring and i just want to be able to do the shit i want and need to do. I often watch youtube to have some sound, but i can't turn it off after, it is also often the same with listening to podcasts. Often when i try to improve it only works for about a week and then i fall back into my same habbits. Do many of you struggle with this, and what do you do about it?