How do i stop a zergling rush as protoss? sc2?

when im playing pvz every single time i seem to get rushed by zerglings. No matter what they always beat me, by the time they come i have just got my first zealot out and creating another. About 6 come and take him out, so i send my probes and they just manage to wipe the rest of the zerglins out. Seconds later...more come. I just cant stop it. Any tips?