OP, you didn't tell us what recovery software you tried.
Normally, people should always clone the drive, but, since this is one of those self-encrypting USB drives, that means your only real option is to send it out to a recovery place, and hope they can do something with it.
(Well, if windows does see the drive, and you don't want to spend big $$$ on a recovery service, then I would use testdisk as a last resort, and let it scan the drive and see if it can recover the partition tables. Do note that if the drive has head damage, this won't work, and could make things worse.)
While this won't help you now, for the next time, you should keep data on multiple drives, and you won't get into this kind of situation where you need to pay some big $$$ to get the data back.
Good luck!