When I was college, I was diagnosed with OCD.
I am sorry to hear that. Which thoughts were you unable to  for more than a short period of time.
I had to study for test but kept thinking about trivial stuff like desk space. So I couldn't concentrate. 
What are the things you were doing at that time.  hand washing, counting of things, or checking to see if a door is locked?
Yes all that stuff. I realized that I couldn't focus on my studies so I got both angry and upset. 
I know the struggle which cause most activities of your daily life to be negatively affected.