Internal storage has vanished, my worst fears?

So after having my trusty Vivid as my main device since March 2012, I think it may have met it's end. Randomly the day before yesterday it rebooted on me, then just kept rebooting.. Only way I could get it to boot up was to dirty flash a CM11 over whatever I had before, couldn't remember if it was CM or PAC. Got it booted up but some things didn't seem to be working right so I did a clean install and upon wiping noticed a message that said "unable to mount emmc" and I didn't think too much of it. I continued flashing gapps and supersu and was able to get the phone to boot and work but certain things didn't work right so I proceeded to wipe and flash again but this time I also noticed that my Internal Storage of my Vivid now reads as 0MB and my external SD is reading as 58254MB or whatever as it's a 64GB. I am having the same exact issue as the guy here http://forum.xda-developers.com/show....php?t=2576897 but my issue is resolved the same way as him. I go to TWRP and I mount as USB but nothing ever appears in My Computer or even Disk Management. I'm relatively certain the internal storage is fried.

Now, if this were the case, how I do I still have about 4GB available for flashing ROMs onto? sdcard0 has no directories and is not found by any file explorers or disk management software that I know of. Somehow I'm still able to flash ROMs, receive calls and texts, and use most of the general functions of my phone except those requiring internal storage (like Titanium Backup).

Does anyone have any tips or advice? Should I try doing any of this from a linux machine or will it not make any difference? What phone should I upgrade to if I can't resolve this issue, because I'm not going to be dealing with it for very long?

Any input is greatly appreciated.