My video files disappeared from ext hd partition

i had my 2 TB ext hd was connected to my xbox one. i seperated drive into 2 partitions...one G: is nfts and titled(works fine and video files viewable) and other L: is fat32(so can be read on xbox360 as well).. one-G: for movies and the other L: for tv shows and music videos.,ext drive has been fine for a couple years now.

The other day the power went out and next day when i disconnected ext hd from xbox one to connect to pc to add another movie,i noticed the one partition -L: that i had named XBOX One TV Video files was somehow renamed with just a drive letter L and folder was empty except for a couple files with weird abreviations and unreadable and 0kb in size.

Disc management it shows both as healthy partitions.. but the partition in question was again titled as just a letter and not as i named it but showed as 70% in use as it should. tho folder empty when veiwed .i scanned for errors but no errors.so files are evidently there yet not. the hide files setting is off so not that.

so why cant i see all my video files or what happened and why is partition labeled L, back to just a letter and not as i named it? i Dont know what to do.i could try recover software but i didnt delete the files they just disappeared. even in windows drives list it shows drive as 70% full but again,only files in it were 4 oddly code titled files of 0 kb size and unreadable. i cant lose these files as they are a couple years of concerts,tv shows and animated movies ive aquired..550gb worth. im hopeful cuz windows says its not empty but just not showing up....

please someone advise and help me restore this drive..the drive is a green microsoft 2TB drive amde for xbox use..PLEASE HELP?