Sounds like you just need to find a new medication.
Concerta or vivance maybe.
Everyone is different. The things you say, don’t necessarily mean that you don’t have it. If you enjoy your tasks, then perhaps you hyperfocus on them.
It’s not uncommon to sit for a long period, but maybe lost in thought? Rapid thought?
I take a stimulant med, but I can sleep and eat and don’t feel agitated.
I had a tendency to be impulsive and seek fulfillment immediately. Often in risky scenarios. Since taking medication, I have been much more reserved. I think before speaking, 50% better. I feel like I notice my surrounding more.
There are non stimulant meds out there, you just need to explore. Doctors can be very med focused, but there are also counsellors who have strategy based life coaching.
ADD/ADHD is not a disease.