On the subject of levels in Star Wars games so difficult you have a nervous breakdown, playing as the Imperials on the Kashyyyk - Islands map in Battlefront (for PS2, if it matters) is damn near impossible to win. The Rebels have a huge advantage, I'm guessing because of the Wookiee reinforcements. I've played it countless times in Instant Action and the best scenario is that I play as a pilot, take one of the Rebel's command posts, then jump back into the TIE, clear a path to the Rebel's main command post's entrance before landing (it's inside a Wookiee house) manage to take said command post (which takes much longer than the other posts) and distract/kill enough Rebel units who try to get inside and kill me. Then, by the time I'm inevitably killed, the Imperials hopefully still have a base with vehicles so I can fly around, pick off some Rebels from the air and keep making sure I've got a base so the Rebels can't win.

In any scenario, there's at least 40 Imperials left by the time all my dudes are killed. If there are any more it's usually impossible for me to win, since they can get enough units to all of the bases to kill me or just spawn right in as I'm in the middle of trying to take their base. I've ended the match with 50-60 kills and no deaths and still lost. I think I might've beat it one time the old-fashioned way by just having an insanely good ground game as a soldier, but air superiority seems the only real way to go.