I understand exactly your issues only too well. I started a bachelors degree at 39 years old because I was wanted a change from working in hospitality. My university noticed something wasn’t quite right with my learning, so suggested I investigate further. I found out I had ADD at 40. I finished my degree last week; I turn 43 next month.
ADD makes us better; we have to work so much harder than neurotypicals, it gives us a stronger character.
I get what you mean about focus and reading the order dockets. Most days I really find it hard to retain information that I’ve just read. Some days are much better than others. I have found sleep to be a major influence on retention and mood. I have started a gluten elimination diet, which does help with my retention when I stick to it. I’m trying this because my mother is a celiac, and so is my brother, so I thought it worth a try.
When you say you struggle with basic tasks, and people get frustrated with you, try to tell yourself that there is no correlation between intelligence and ADD. We have to work harder to fit in in a neurotypical world, and we are playing by rules not setup for us. There is a good chance you’re probably not interested in the task they are asking you to do, which will make it almost impossible for inattentive add types. Our brain activity slows down when we try to do tasks that don’t interest us (I’m inattentive), and it’s like a constant battle.
I’m reading “Change your brain, change your life” at the moment and am finding it very interesting, with lots of suggestions to help us out.
I hope this helps, but remember your not alone!