Hi jhseale1,
Have you tried closing it from Task Manager? What version of Windows are you using?
Try the following:
Simultaneously press the Ctrl+Alt+Delete keys on your keyboard
Click Start task manager
In the Applications tab, select the browser application with gmail open
Click End Task
In the window that appears, click End Now
That should close gmail, and when you reopen your browser and access gmail again hopefully it will work correctly.