What TK2011 said, missing GPS metadata shouldn't be the end of things, unless you're saying your photos are all gone, again?
Did you ever replace your SD card, say with a Lexar, or something solid?
While my phone consistently creates formatting errors on my card (which I've checked a couple of times, no errors outside of phone with surface tests), it doesn't lose photos. It's VERY slow to read them from the phone via USB though, crazy slow, like others have mentioned...