For future reference, prime your beers by weight of priming sugar...there are plenty of calculators our there that take into account both the volume that you are bottling, as well as the temperature (which is a surrogate for the CO2 that is already dissolved in solution from fermentation). I use
this one, which I also find handy as it incorporates a reference of recommended volumes of CO2 for various styles.
In regards to your current problem, the one time this happened to me, I ended up using super cold temps and very slow, careful openings, and still lost a bunch of brew. I ended up using the last three 22 oz bombers to try the freeze concentration technique...came out pretty good, even if it wasn't something that I would want to try/drink all the time. Perhaps you could try it yourself with some of the remaining bottles....