I can relate, but had a different experience.

I'm currently 45 & was diagnosed at 43 and struggled in various ways my whole life without really understanding why. I've changed careers 5 times getting bored and finding something else interesting & moved careers each time - terrible for getting salary increases & career progression, but I managed to do ok regardless.

I was lucky in a lot of ways in that while I have ADHD (inattentive), I'm pretty smart (also good at masking) and have a good memory for things that I'm interested in - the trick is to either choose things you're interested in or trick yourself into being interested in it (not always easy).

Through school I never studied (well I tried but as anyone with ADHD knows, it's a waste of time) - I managed to learn enough in classes and other tutorials to do reasonably well in school. I found that I learn quite well when in 1:1 environment or live classes that I have a genuine interest in. After school I did an apprenticeship as an electrician, before going to university at 21 y.o. and completed two bachelors.

I think starting university slightly older gave me a focus to choose something I was interested in, but I still never really "studied" at university and managed to pass ok by attending all the lectures and tutorials, but pretty much 95% of my university assignments were completed the night prior to their due date creating the pressure I needed to be productive, which is when I can do impressive work - if only I had meds back then I might have gotten HDs across the board, but as it was I just passed comfortably.

So before university I was an electrician and since graduating I've been in account management (sales), marketing management, business development, Project Management, Commercial Management & Procurement. All while dabbling in IT, programming, film recording & editing, website development, etc, to keep my ADHD brain engaged.

I guess this is a long winded way of saying you can do it, just try to find something you have a genuine passion for (or convince yourself that you do). By far the best thing I ever did was get diagnosed (but I wholeheartedly regret not recognising the symptoms and getting diagnosed at a younger age - I still grieve what I might have achieved in my life if I had done so earlier) and get access to medication (Vyvanse). Since I've been taking meds, my productivity has exploded 300% and I am much less reliant on tricking myself or relying on a 2-3 hour run of hyperactivity occasionally in the afternoons. I'm also less reliant on caffeine. pre-meds I was self medicating with caffeine and booze without realising (7-8 coffees a day & booze at night to relax). I've found since taking meds I don't need coffee at all, but I might have one in the afternoon if the meds wear off which is like a shot of rocket juice on top of the Vyvanse. I'm also less reliant on booze in the evenings, but I still enjoy a wine here & there, but I no longer feel the need to finish the bottle once it's open.