Everyone is saying ADHD, but I wouldn't say that because you don't give enough context. I also start doing things that just come to mind, and after a month I change peojects leaving them unfinished. But I think it fairly normal some ppl just have a harder time dedicating all their time to one project. I'm juggling 3 projects as I'm writing this and I'm overwhelmed, yes, but that doesn't change the fact that I can pay attension when I'm doing one of the three. (ppl who have ADHD usually can't)

If you just fantasize doing thing, but never do that's also not the sign of ADHD, I did yt baack in the day. Now I don't, I don't even think about it. The solution to "wanting to do stuff, but not doing them" is quite frankly to do them.

What i'd do in ur place is get some video editing software, recording software, and something that can make easy content, like for example CS:GO. You could record CS:GO however you'd like and edit the footage however you'd like. Do this until you enjoy it, and congrats! You did something maybe learnt something, maybe made new friends, maybe discovered a secret talent. This is life buddy. "Fuck around and find out."