Welcome to the forum. :flower:
Did this get fixed?
If not, then yes, you are probably screwed. Sorry. :sad:
Why did you have the computer open while it was on, again? You should always turn it off when doing any internal maintenance, no matter how insignificant.
Your best course of action is to immediately buy a new drive, restore from your backup (you do have a backup, right?), then get an enclosure and place the malfunctioning drive in that, where you can possibly run some tests on it. Or you can leave the drive in the computer as a secondary unit and do the tests that way. The important thing is to get back up and running.