Is there any possibility to recover my lost encrypted file?

try this: learn.microsoft.com/.../recovery-process

Yes, Emma don't be upset you can get back your BitLocker encrypted file. If you have a BitLocker password or BitLocker recovery key you can get back your lost files. Because to unlock BitLocker encrypted drive you have to use one of them. In case if you lose your BitLocker recovery key also forget your BitLocker password. Then you need to take help of BLR BitLocker recovery tool, this tool can find the BitLocker recovery key that is stored on your PC. The tool is completely safe for recovering lost encrypted files. Any type of user can make use of this software to recover files. Users can check more features of this software on the official website.