How does Ironman "perma death" mode work exactly?

Does the perma death only apply to your squad mates?

I started a new campaign and died at some point but I kept all my progress and got to retry the same mission like nothing happened. Is it because I was playing normal mode or is Ironman mode basically forcing a game save after each mission you survive, taking the chance to undo mistakes?

Bonus question if above is true: If the raid goes horribly wrong and multiple officers die, I can just kill myself and have a fresh try, or do the officers stay dead then?