before three weeks i used some 10mg SR RETALIN like 10 tablets , it helped me alot to focus for 3-4 hours then I got tired when its wears off, and its okay.

but before somedays, I got concerta 36mg tablet that last 10 - 12 hours to study for exam.

the first day i wakeup optimal and so excited then i took the tablet, it worked fine I focused I had the energy to easily pass the day but it was not as pleasure and calmed as retalin SR ( in this med i feel like i am very focused and optimal )

second day : the exam is more close the and i started to feel stress because this exam is so hard and super important for me and I have to pass it. So i wake up in the morning, before i took the CONCERTA I was so worried and nervus . then i took the tablet , instead of focus\pleasure\calm that I expected day before I became so nervous.is that because the exam is close and i am so afraid of it?

or it's because this medication not working if your actually stressed and before a very important exam.