Great job on that level of accuracy! The score definitely doesn't properly reflect that (even accounting for difficulty levels) but I do think that there's an explanation here.
First off, just in case you're not familiar, the GMAT algorithm punishes you harder for missing easy questions, but less for missing harder ones. Several commenters have already brought this up. But this is still quite the glaring gap.
What likely happened was that every question you missed was an easier one,
and you got every
experimental question correct. When you see the score reports of others (who scored higher despite missing more questions) it's not just that the questions they missed were more difficult, but also that some of the ones they missed were experimental, and therefore didn't count. Let's say there were a total of 5 experimental questions in the section that you took. Someone else (assuming they got a very similar ordering of questions) could have gone -8, and scored a Q80 simply because they missed every experimental, so they actually only got -3 in the eyes of the algorithm. But in your case, every question you missed was a real one, so you would actually score lower.
Overall, definitely a rough outcome, but this demonstrates that you can definitely pull off an excellent Quant score next time.