Flooded with ideas

Sometimes it is hard to conceive ideas while the other time you are flooded with ideas. Both cases are troublesome.
Once in my Exam at MSc in Nepal, that was my last exam of the year, I was reading the question paper. I never used to read question from top to bottom at first sight. I don't know why I just wanted to try it because it was my last exam and in other I had done very good if not excellent.
I looked into the questions and as I looked into them, the ideas of how to do them started right away!
I started to think: Yes... I can do this this is like this+this and that and similarly, for all of them. Imagine having seen all questions and the ideas already playing in your mind: how to write?
Because I had to write and to write I needed little noise. The noise of idea simply overwhelmed me and I was flooded! I was swept away and after that moment my processor just stopped working. I wanted to write but I could not. A single letter. My mind had become a place like hell. I then felt at the very moment my deep inside saying "what is wrong with you?" while the feeling that I was "bleeped".
I stopped, took deep breath and laid aside. My friends noticed, but what else? I requested water and then after drinking some tried to chill. I walked outside the hall a little bit again took water but believe me it was really hard to calm down the agitated mind.
The very first feeling of being so nervous in my life nearly swept me away. I had choice to cancel the paper and walk away: But I decided to go with it. I passed as satisfactory but flooding was witnessed and I was in trauma for one month after that exam.