Mac starts up to an Apple logo or progress bar

Hi,

I use iMac with the Monterey MacOS.

MacOS loading too slowly, about 1.5 hours, after that I see working desktop, apps are loading, but to slowly and after that everything hangs.

I used disk utility to check errors and fix, but everything is fine - no errors.

I tried to reinstall MacOS Monterey but the situation is the same.

it installs, I see progress with the time, but then the situation the same - it loads too slowly.

it happened after problems with the electricity.