I have no near-drowning experience, and don't have any knowledge or opinion of the aquatic ape theory. However I did for a few months after an illness have a period when I'd experience relatively minor asthma-like episodes. And even with those relatively minor episodes which were very far removed from actually inhaling a bunch of water, there would sometimes be a point where there was a deep primal feeling of panic over the (very temporary) inability to breathe.
Yes waterboarding is torture.