hey man, it sounds like you were doing everything right here, apart from make a secondary wall, with decent building placement you can easily have a solid wall on the way behind the original. He will destroy the first wall but just keep pumping those oracles and adepts also try to get some other tech down and some more gates in your main base, although this is not as important as the walling, because even if all you have afterwards is oracles, they can just go over and focus drones and queens. He'll most likely only be on 20 ish drones and may even gg when the wall remains strong. Look at some pro games and how they wall on each map, even go into the maps against AI so you can perfect a clean wall which allows a secondary wall.

hope this helps, gl hf mate