By "mission" I mean one round of combat.
For me, it is one where you are seeming to have very little success in the game, and while you may get hits and even kills, you watch helplessly as your side's tickets drain away, yet while your side seems to be dying around you, and surely you keep dying, there always seems to be enough points to spawn again into hell.
It has seemed to me like such missions tend to string together, as are days when I can do well for a team that returns the favor.
For today, I did figure out that I still had facebook up while trying to play War Thunder. That was killing my framerate, and I think my game's performance in other ways as well. I may also be having a bit of a problem with depression. If I got on anyone's nerves today, I do apologize. I know I allowed the game to get on my nerves in a way that I should not.