issues with Mac

I was trying to clean my hd in figuring that would fix my issues with slowness and clean whatever that might be on the mac , but can't seem to reinstall Mac os el-capitain. When erasing the hd for ox x extended journaled it managed to do it and thought everything was fine when reinstalling el-capitain.

Just when I was asked to sign in to iTunes it was loading slow and had to force shut down.

After that I keep on getting an error message telling me that I don't have the packages to install el-capitain.

The hd appears to be fine when it's labeled as Mac hd. But the Hitachi hd media part is not being recognized or repairable on the info list.

The hd can't possibly be fft if it's still booting and able to go on recover mode so what would be the problem? Any help will do. Thank you.

(it's an early 2009 version of imac if anyone was wondering)