I dont know how to counter myself!

I mostly play vs my friends to set up good strategies but today we decided to go 3vs3.
We all played as zerg and did cheapy zergling rushes, the only thing that delivered any problems was a terran block with scv's behind it or a bunker filled with marines. but our 18 zerglings killed every single person easily so 1 out of 3 would be down for sure.
The bunker strategy we would make a baneling nest and transfer our zerglins into banelings and spawn 14 zerglings to back them up. so we steamrolled the terran defence with banelings and rush the mineral line with zerglings. it really sounds quite cheap but it was effective!

So my question as a Protoss player is: In a match where a zerg player would use this strategy and i dont get to a stargate fast enough. How do i counter this? (because I personally think a protoss player cant make a defence like terran can with bunkers and scv's repairing so i dont use it)

Because zealots and stalkers get eaten for breakfast by banelings and the additional spawn of zerglings would destroy my whole economy or worse.

 

I've used the Zergling->Baneling strategy myself with friends. The only time it didn't work is when a Protoss player we were fighting had two Colossi and a handful of Stalkers standing behind the Warp Gates blocking his choke point. I managed to destroy one of his Warp Gates, but at least half of my Banelings were fried by the Colossi, not to mention all the Zerglings my teammate had made to back me up.

We ended up winning that match, but only because both my teammate and I had teched to Mutalisks and our opponents had focused primarily on building ground forces (I assumed they were overreacting to our constant Zergling/Baneling rushes). If the Protoss player had made air units instead of spamming Immortals/Stalkers/Colossi then the game probably would have gone on a lot longer.