Biggest obstacles, challenges, mistakes, and successes

The biggest mistake I made was initially writing my thesis about characters with physical disabilities because there was barely any information for a twenty page paper. The biggest challenge and obstacle is choosing which works to to use and which to discard because I have found a vast amount of information regarding my topic that easily can exceed twenty pages. I do not want to use too much so I have to choose the best. Although this a challenge I have succeeded in finding many works portraying characters with mental disabilities in literature.