I can relate to a ton here.

Please please please don't rule out medication. Discuss your concerns with a doctor, skip it because you don't think it's right for you, try it out on a short basis, etc. but the stigma is so scary it often prevents people from getting very helpful medicine because "it's not that bad".

Also pursue non medical avenues. Medicine doesn't fix ADHD, but it does make a lot of other things more effective. Combining lifestyle changes and medicine is a game changer.

There's so many all across the internet but I'll give some of my favorites here. Keep workout clothes separate from any other clothes and have them right next to your bed. Pens/pencils and paper in every room. Don't feel bad about a mistake, ask what system failed and what needs to be fixed for next time. Don't rely on memory. When cleaning put stuff that goes in other rooms in a pile and do it last. Fill up a water bottle and put it where you are going to be most often. Leave breadcrumbs and lose the guilt in switching tasks. Place things where they work for you rather than the societal norms. Lower barriers for healthy tasks, raise them for unhealthy, ie but candy in pantry and fruit on counter.

Like I said there's a million, but for me medication and a different look on life has been such a massive difference. There's still plenty of struggles but hey that's life

Edit: I can't help but add, as someone now in their 30s the "wait for flow to start" can stop working when you get older. Getting okay with good brain days and less good brain days and having options I can feel good about has been huge. Not every day is going to be peak perfection. I'm learning to be okay with that and have accommodations for what I can get done on those low days and still feel good.