Individual responses to medication are so varied, even in best circumstances, it is trial and error.
I was really lucky in how systematic my first MD was… instead of saying, “You look like a XX mg of YY medication”, he started me on methylphenidate and titrated my dose.
This means that I did 5 days at 5mg, 5 days at 10 mg, etc.
I also kept a log of my blood pressure, positive benefits, and side effects. I got to 20 mg, had too many side effects and stopped after day 3. My prescription was then 15mg, maximum positive benefits and no side-effects.
Once that was established, we looked at how long it worked, my crashes, etc. Then played with a second booster dose, systematically.
Keep in mind that this was over 25 years ago, so our medications options were more limited. The roller coaster you experienced before extended release was no joke.