External HDD with raw corrupted file maybe due to overwriting

Hey guys, I have a corrupted external hdd. Mine is a Transcend storejet 500gb external hdd. There's a backup button outside the hard drive which my nephew pressed. The storage left before he pressed that button was around 20gb. So I thought maybe after he pressed the button it overwritten my files hence the raw data output. And every time i connect my external hdd to my laptop, MyComputer freezes and the name Transcend (as its driver's name) is changed to Local drive. I've already did 'marked partition as active' but i haven't formatted it yet.

My question is, do I have to backup this corrupted drive? Because I don't have another spare of spacious drive. And If I don't when I format it, do the files are still gonna be there?? or another recovery must be done??

PLS HELLLPPPP...sooo desperate here. :(((