What fear/nightmare does Steve have in Monster?

In Monster, Steve Harmon is in almost a constant state of fear until the trial ends. His film helps him cope with the various fears. While he is incarcerated before and during the trial, he fears that the other prison inmates might attack or rape him. He does not want to sleep because he fears that he might not wake up.
One thing he especially fears is that he will be found guilty, which would likely result in spending many years behind bars. He also fears that he is the “monster” that the prosecutors make him out or that he is changing into that creature; he does not recognize himself in the mirror. Steve suffers panic attacks that leave him breathless.