Can't boot or wipe iMac 2010

I have an old iMac core i3 2010 that I am trying to wipe before getting rid of. I've signed out of everything but can't wipe the data fully and now it won't work at all. The only place left with data still on it to wipe is the disk image but that's where the OS X operating system is so I can't wipe it.

I tried booting it in Recovery mode to reinstalling mac OS elsewhere but it gets stuck after doing internet recovery on a screen with the apple logo and even when I've left it for hours it doesn't do anything. It now automatically goes into internet recovery and then the apple logo if I use command + R.

It's now not letting me boot it up as normal either and when I try it gets stuck on a circle with a line through it.

I have also tried:

Command + D for diagnostic mode but it is too old a system to run this so comes up with support message 3403D.

Command + S but after showing code the screen glitches and I'm left with fractures of code combined with the circle with a line through it.

Safe boot but this also has the circle with a line through it.

I just need to know if any of my data would be recoverable or if I need to fix so I'm able to wipe it properly and if so where should I start! Thanks