My flash drive is now full and everything is showing gone

Please tell me you can help me. I was in the process of copying pictures to my flash drive and it prompted me that it was almost full. When I went to check the GB left, it would not open and said FAT32 below the Flash Drive. I closed out of the window and reopened My Computer and it now says Removable Disk (E:). When I click it, it tells me to insert a disk. The files are NOT hidden and Device Manager shows it still exists, but when I do the cmd instructions you have given other people to do, it won't change the drive name. Every letter I do says that the batch file does not exist