How to unbrick my device (yuphoria)

I was using CM 13 nightlies for the past few months, everything was working fine without any issue but day before yesterday all of a sudden my devices rebooted and showed something like device encrypted or something like that. Being unable to use my device I thought i should change my ROM to a stable one so i went into twrp and tried installing new ROM but to my surprise the internal storage was showing 0Mb. I searched internet about this issue and did something like formatting data or wiping everything except the storage. Nothing seems to work and i keep getting this error which says * "unable to mount /data (invalid argument)" * "unable to mount /cache ( invalid argument)" here are the screenshots: Screenshots (click images for larger variants) I even tried flashing the stock ROM through fastboot but that also seems to be not working. It is failing to write system partition and desplaying this message FAILED (remote: flash write failure) Here is the screen shot  Than i tried adb sideload. This also gave me no luck. Here is the screenshot of the process. Now I feel hopeless :( Any help would be much appreciated.