iMac not booting up

While I was rendering a video with Adobe Media Encoder I decided to deactivate Wi-fi. After a while I tried to activate the Wi-fi and it didn't worked. I waited till the end of the rendering to try again and it didn't worked too. I decided to turn off the iMac. When I powered it on it was not working, it kept booting up and the bar (under the Apple logo) even if it was full it was not starting the iMac. It was stuck for 5 hours with nothing happening. I tried the Recovery but no error was found and also tried to reinstall macOS but didn't have enough space. What should I do?