Most of us have done this at some point, I lost all my photos of my honeymoon because I didn't back up.
I now backup in triplicate, I have my main HDD which syncs certain folders to my NAS and also I pay a small amount of money per month for unlimited online storage where I also incrementally sync said folders. Always remember that a hard disk drive WILL fail. (Although I am aware this is not what happened here).
Hope you get your data back.
While I agree HDDs will fail, the signs of failure via SMART are early and Windows will warn you if a threshold is triggered during OS oeprations or the BIOS will at boot.
Note that HDDs that are always on will last longer than drives that are powered up and down multiple times a day. Ever since I stopped turning my computers off I have never had a HDD failure. This is going back to the old Barracuda and Maxtor days.
Keep an eye on SMART and all will be golden. CrystalDiskInfo is a good utility for monitoring the SMART attributes for any given HDD/SSD.
I don't use online storage solutions, I don't really believe in them (personal preference) and as such have external HDD backups of each main drive. I do monthly backups and system images. It's extremely unlikely that both main and backup HDDs will fail at the same time.