If you were on a 50 amp service, then it sounds more like the loss of neutral so that there was 240 volts across your appliances. Doesn't change the fact that your appliances are fried, though.
Since the breaker will not reset, I'd bet the converter is gone, as well. Damage is internal, as it is with all electronic devices.
Make sure you check ALL the appliances in as many of their operating modes as you can. Anything that was 100% turned off, which doesn't include a lot of things like tv's and stereos, and control circuitry, may have survived. This PROBABLY includes 12 volt devices, too, but I'd check these anyway.
Until you get the converter replaced, make sure you get a good battery charger so you don't run the batteries down too much.
Document everything, and test everything, and good luck.