Native Son question

Two things I questioned most, in terms of Bigger's actions:

What was that thrill and "excitement" that he felt at times? (seeing the white girl drunk and taking upstairs, when he saw the investigators searching for clues, etc.). It seemed to stop once they figured out it was him. Was he getting the "movie screen" life he longed for during those times?

More baffling: Why didn't he kill himself? He suggested it a few times after they finally suspected him, but he never pulled through.

What are your thoughts on his actions?