Unable to reinstall Mac OS X

A folder with a question mark means that the selected startup disk isn't available or doesn't contain a Mac operating system. Learn how to resolve a flashing question mark.

I read your whole post but most of it was hard to understand and seemed confusing. Thus, I sent you the standard fix for the stated problem.

Here is a possible solution but it will erase your disk. You will need a functioning Internet connection by Wi-Fi or Ethernet. The latter would be preferable.

Internet/Network Recovery of El Capitan or Later on a Clean Disk

     If possible back up your files before proceeding.

1. Restart the computer. Immediately, at or before the chime, hold down the (Command-Option-R) keys until a globe appears.
2. The Utility Menu will appear in from 5-20 minutes. Be patient.
3. Select Disk Utility and click on the Continue button.
4. When Disk Utility loads select the target drive (out-dented entry w/type and size) from the side list.
5. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.
6. Set the partition scheme to GUID.
7. Set the Format type to APFS (SSDs, only if installing Mojave or Catalina ) or Mac OS Extended, (Journaled.)
8. Click on the Apply button, then click on the Done button when it activates.
9. Quit Disk Utility and return to the Utility Menu.
10. Select Install OS X and click on the Continue button.

This should install the last version of macOS installed on your computer. Note that if you get to the point where you would be reformatting the disk and no disk is visible to format, then the disk has failed.

Is there anyway to retrieve the data from a crashed internal hard drive then?? This exact same issue happened to my exact same 2012 model of MacBook Pro a few days ago it was super inconvenient to say the least.

General File Recovery

If you stop using the disk it's possible to recover deleted files that have not been overwritten by using recovery software such as Disk Drill, MAC Data Recovery, Data Rescue II, File Salvage or TechTool Pro.  Each of the preceding come on a bootable CD to enable usage without risk of writing more data to the disk. Recovery software usually provides trial versions that enable you to determine if the software would help before actually paying for it. Beyond this or if the drive has completely failed, then you would need to send the drive to a recovery service like Drive Savers, which is very expensive and does not guarantee success.

The longer the hard drive remains in use and data are written to it, the greater the risk your deleted files will be overwritten. Unfortunately, these programs do not work on SSDs.

Also, visit The XLab FAQs and read the FAQ on Data Recovery.

Your internal drive has bit the bullet. You need a new internal drive.