Application is unresponsive, and cannot be removed (unable to Force Quit / restart mac / uninstall app)

I am having trouble closing the following application: Opera GX. The Icon on the Dock displays the "Application Not Responding" message.

I tried to Force Quit but it wouldn't do anything (I tried Force Quitting using the shortcut Cmd+Q, Force Quitting by right-clicking the application on the Dock and selecting Force Quit, as well as Force Quitting manually using the Force Quit applications tab on the taskbar, none of those ways worked, and the application is still open).

I then tried to shut-down/restart my mac, but it wouldn't do either (likely because it can't close Opera GX, but no error message was given, it just won't shut down).

Finally, I tried to uninstall Opera with hopes of reinstalling it, however, it won't uninstall, displaying the message " The item “Opera GX” can’t be moved to the Trash because it’s open.".

Any help would be much appreciated!