Sounds like you guys toughed it out pretty well, but I also think that you were trying a little bit too much at the same time. I don't see any real "problems" here, other than issues that will resolve over time. Obviously you are not familiar with your equipment yet and the mere fact of doing an unguided dive added to an existing anxiety. If I were you, I'd take it easy and start doing shallow shore dives, where you don't have to descend into deep water(!), where you don't have to worry about compass navigation(!), wrecks(!), currents(!)and all that. There were just too many demanding and new challenges in your first unguided dive. Take it slowly, one new "challenge" at a time, and you will both become ever more comfortable. As to the question of oxygen toxicity, I'd say No way. Of course you can never say never, but IMHO, you were way too shallow for that being a possibility. "Freaked out" is much, much more likely. There is no problem with that. Look at your experience as "placement test", learn from it, take it slowly, and have fun!!!