My Mac is stuck on the Apple logo and the loading bar

otherwise you can try these actions:
Launch the startup manager: Hold down the Option key at startup.

Start without extensions: keep the shift key pressed.

Boot in Target Disk Mode: Hold down the T key.

Force boot into Mac OS: hold down the X key.

Boot in verbose mode: Command + V.

Boot in single-user mode: Command + S.

Hello, good evening

Having encountered a similar problem recently and searching (a lot, for 3 days) on the Internet, nothing worked, my iMac refused to start and kept freezing.

I came across this topic, I tried jumulka's technique of resetting the PRAM (10 times), but I only restarted it 5 times fearing that 10 times might be too much.
After that my computer was still stuck BUT by restarting it one more time and entering Recovery mode (CMD + R) I found OS X Mountain Lion while I was on El Capitan.

I then formatted my hard drive and installed OS X Mountain Lion on my Mac.
Downloads completed, installation completed (you have to be patient) and my iMac is like new with all its performances. I think that resetting the PRAM 5 times downgraded me to OS X Mountain Lion, which isn’t such a bad thing.

There you go, I hope this can help someone who stops by here looking for an answer.

I don’t think I’ll reinstall El Capitan which brought a lot of problems to my iMac. Yosemite will suffice.

Have a good day, evening