about banshee harass or stargate pressure. You need to improve your scouting and learn how to react to specific things. Extra queen's are better early game [less larva spent on defenses, and additional utility] than Spore Crawlers but you will usually need one per base [two at the most] in order to spot cloaked banshee's or prevent your queen from being lifted. If you want to play it extra safe you can just ensure you have an Evolution Chamber building around 7 minutes.
A couple dailies that should help you:
Note: Players in lower leagues will often overcommit to something like Void Rays or Banshee's and that leads to you losing because you simply dont expect them to do it. The best counter is again scouting, once you see that you can react accordingly [Mutalisks deal with both Void Rays and Banshee's relatively well, Hydras should be a last resort vT but can be used to great effect vP. Finally, Fungal Growth is incredibly good vs Air Units because they tend to clump up]