Stuck on loading screen

Hello and thanks in advance. My iMac turns on just fine, but not only the loading time it's extremely slow, but once the loading bar is full it doesn't get any further than there, aka it doesn't move on to the the password screen.

Booting the PC in safe mode led to nothing, so I tried to use macOS Utilities.

I've tried to reinstall the OS, which didn't prove effective. I've tried to use Utility Disk, "First Aid" on each and every available disk, but this also proved to be ineffective.

I'm ashamed to admit that I don't have a Time Machine Backup, as I discovered its existence, I'm afraid, a tad too late.

What other procedures do I have left? I will also attach some photos which, despite their abysmal quality, should however also give additional information.

Sincere thanks in advance.

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After more than twenty minutes of waiting, this is what I'm greeted to. Leaving it this way for two consecutive days has also proved to be largely ineffective.

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The status of my Mac right now. I probably should have considered erasing some junk...

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I have a Windows partition. It, however, loads perfectly fine and has no issue whatsoever. If it can be of any use, I have access to it.