>take 20mg of retarded methylphenidate in the morning
>go about my day
>drink water, eat enough, dont take other drugs, be moderately active
>come down sensation sets in as expected
>go to sleep

On the next day I have a headache like sensation, I'm more sensitive to noises, subjectively my ability to focus is subjectively worse.
If I take another pill it does its job again, but to a lesser extent. The side effects are increasing with continued use to a point where I just want to get off it.
Obviously I stop using it.

Now whats causing this? What can I do against it? Has anyone been in a similar situation?

Im being prescribed "Ritalin Adult", im thinking about asking to try out a different version.