Was I banned in Fortnite?

When I start the game, the loading screen comes forever and I'm back in the lobby. I also can't get into voice channels, but I also didn't receive a notification that I was banned or that way. Other accounts would not have used a glitch several times

So taking advantage of a glitch is actually not allowed, so you may have been banned. But it is very unlikely.

I rather believe that it is because of your internet, because in the corona time everyone is on the internet and it is overloaded.

Maybe. You can restart your router at home with the push of a button or you can switch the WLAN on your Pc / XBox / Ps4 off and on again.

Or you drive the console down and up again.

I have already restarted the Internet and everything is actually not because of it