Hi Mary Reese,
BitLocker is a Windows security feature that protects your data by encrypting your drives. This encryption ensures that if someone tries to access a disk offline, they won’t be able to read any of its content. More information can be found on BitLocker overview.
Please visit Find your BitLocker recovery key for more information about finding your BitLocker recovery key. Additionally, you might have a backup on a file on an unencrypted partition, external drive, or cloud drive.
You can visit the page or aka.ms/recoverykey on another device then sign-in with your account to view BitLocker recovery key then enter it to your computer. Please kindly check for BitLocker recovery key on all accounts that you have.
If you forget your BitLocker password and cannot find BitLocker recovery key, then no one even Microsoft can unlock your drive or restore BitLocker keys. It's how BitLocker was designed to protect your data.
I hope that above information is helpful to you.