I've been struggling to formulate a response to this. I'm in the process of getting an ADHD diagnosis myself. Well, I'll probably get one, can't know for sure. Either way, I've had very similar issues, especially when I first started out.
For me, it's all about two things: Habits and caffeine.
My goal is to always do something every day. If that turns out to not be very much at all, I still pat myself on the back for a job well done. Because I maintained the habit, i safeguarded it, it's still there. That's the important bit for me, positive reinforcement instead of getting mad at myself for not getting as much done as I wanted.
One has to accept that it's a marathon and not a sprint. You won't get good at any of this in a day or a week, just let it build up little by little over time, and make it a habit to just do something every day.
As far as caffeine goes, for me ~200mg per day is good, that gets me about 2-5 hours of decent focus. Any more fucks with my sleep, and once your sleep worsens, you want more caffeine, and it spirals from there. I can't speak on the edibles mentioned above, since I haven't tried it myself.
All that said, every brain is different, so all you can really do is try a bunch of different things and see what works for you. The things I have mentioned work for me, and may be worth trying, but there's no guarantee they'll be of any use to you.
Oh, and I totally recommend something like LeechBlock NG, it allows you to block certain websites over specific time periods. Absolute lifesaver for me, can't get anything done if Reddit is available for procrastination.
And a final note on tools for organization and such. I've just accepted the fact that my brain thrives on chaos. It loathes organization, any attempts at it lowers my enthusiasm to do anything at all, and as such will ultimately lower my productivity. Chaos on the other hand feeds my imagination and helps me come up with interesting things to do with the story/game on the fly. If organization doesn't work for you, try to simply embrace chaos.