Hi Inak, I felt the same as you.
Diagnosis for me was a great thing, helped me be less critical of myself and be kinder, and say “well done you’ve struggled more than most people in life so far. Well done for getting this far and still achieving stuff”.
Diagnosis doesn’t need to lead to medication. I took a 6 months to decide, the doctor didn’t force me until it was my decision. CBT and mindfulness and reading Additude and Books about adhd was how I coped first. I didn’t want meds.
Then something changed. I kept reading about meds being like glasses lenses that don’t take away the sight problem, they just help you to read with less stress. So i tried 3 types of meds over the next year on a very tiny child’s dose because I’m highly sensitive to medication (like you i get side effects v badly) 2 types caused v high blood pressure and I had to stop. I felt awful. But now I’m on a child’s dose of Elvanse and have had no problems so far! I am too sensitive to tolerate an adults dose so i have to use lots of other coping alongside to manage daily life and adhd symptoms. I’m glad I chose meds in the end, they have taken the edge off the racing mind and restlessness.
If you do ever try meds make sure they regularly monitor heart and blood pressure in the early stages and start on a very small dose. I was 3rd time lucky. And I don’t think the other 2 meds caused me long term damage because I stopped as quickly as poss.
Take care and get diagnosed one day at least it will make you feel better about yourself over time…