imac wont finish loading just halfway through the apple screen

Tried everything isn't very helpful because if you really tried everything there's no advice we can give you. A list of the ways to boot that you've tried to solve it would be helpful.

Have you tried starting in Safe Mode and see if the problem still occurs?

Use safe mode to isolate issues with your Mac - Apple Support

Restart holding the "shift" key.

(Expect it to take longer to start this way because it runs a directory check first.)

Have you tried Recovery Mode? If you can start in Recovery Mode choose Disk Utility > First Aid and repair the hard drive.

About macOS Recovery - Apple Support

Let us know. Also, give us the specs on your iMac, what model year and which OS are you running?