I'd recommend getting more familiar with the timeframe before delving too deep into historical fiction or journals. Context is important when it comes to history, after all. If you're interested, these two videos by Oversimplified would get your foot in the door: Napoleonic Wars Part One Napoleonic Wars Part Two
He breaks it down into digestible chunks and doesn't really go too in depth but it is a good launching point!
You're not wrong. Enjoy it! I haven't read it myself (mostly because my grandmother is a history teacher and I can't take much more)