I think it should be relative to the person's abilities. 8 hours of work, laundry, 50 minutes focussed studying, healthy dinner, remembering aunt's birthday and bedtime at 10 might seem reasonable to most. Some with ADHD might also pull it off. For others, their best is to do one of those things after work.
Different people, good and bad days. Absolute measure & judgement for everybody is the problem.
Stimulants having a calming effect is not an absolute must with ADHD.
I can only recommend to keep going for an official diagnosis & treatment. It's the single best use of your time. Cheapest, even free, is the way from a psychiatrist, with a referral. But you probably noticed that it's nearly impossible to find one.
Very nice and completely remote is GAM medical, but it's not paid for by GKV. I got the impression that it's pretty thorough and responsible. Not fast though; if you start now, it would still take months to get a prescription, if necessary.
Quite shady and only technically legal are sites like expressdoktor.com. They take advantage of the fact that any EU doctor can write a prescription that works in any other EU pharmacy. It works more like a webshop, pretending to include a doctor consultation, and it is certainly not safe. Especially the only ADHD drug they have, Modafinil, would require a thorough consideration and check-up when used for ADHD, because it has significant risks. It's the fastest way, but I don't recommend it.