Studied for weeks, exam went badly, now I feel awful

I recently started taking Ritalin after being diagnosed and prescribed it. Right now I have final exams that will determine my final grades for several subjects this school year, so I had been preparing for weeks—especially for History, Logic and Spanish.

With all that studying, and with the Ritalin helping me focus, I really thought everything would go well. I had learned the material better than ever before, but when I took my history exam, there were barely any questions about what I studied. Instead, there were a lot of questions about economics and topics like that.

Now I feel really down and frustrated, like an emotional crash. It feels like all the hope and progress I had while studying didn’t really matter, and that’s been hitting me hard.

i was wondering if this feeling have something to do with Ritalin? And does anyone have advice on how to feel better after something like this?