Unlucky rolls

[Garlyle]

It's just RNG. Everyone has good and bad days with RNG. The best I can say - though knowing full well it's no comfort on those bad days - is that you just get used to it. RNG doesn't hate you, it doesn't have anything against you or any special systems set in to spite you. It just is.

As for your second question, Need's availability is entirely determined by which class a player is in. For that reason, the best way to get relevant items for your class is to actually run as that class, or you risk someone Needing it away from you. Shared items though (Crafting materials, minions, sands of time, etc.)... nothing much you can do.