Calling mask goggle or fin flipper is very different than calling air oxygen. For a non diver, that is another story, a diver should make this very distinctive. It can be life or dead. I believe and hope dive course in very language make this very clear what we breath in out back is NOT oxygen.
The OP calling air “oxygen” in his original post was part of what prompted me to suggest either an OW do over or at least doing some reading. That together with the over-reaction to the supposed DCS hit made me think he really needed to refresh himself on a whole bunch of from OW - which he did at 14 and is now 22. We don’t know if he did a refresher.