My pages won't let me quit and I cannot restart my mac. What Should I do?

Pages Version: 5.5.2

Processor: 2.5 GHz Intel Core i5

Memory: 4 GB 1600 MHz DDR3

Macintosh HD Version: 10.10.2

Capacity: 498.88 GB

Available: 387.41 GB

I've had this laptop for about 3 years and have notice it significantly slowing down, having many non-critical graphical glitches such as the lock screen not working properly, and just acting strangely. I think it is because I have been using it and running heavy applications more frequently now.

Here you can see that pages is running, but there is no clickable option to quit and restart.

Here you can see multiple pages windows. The "Done" button doesn't work, and I can't close them. They also were glitched so that the bottom part was transparent (I couldn't get a screenshot of it).

I have tried right clicking on the icon in the dock to quit, clicking on the done to quit, Command Q, and clicking the "quit" in the drop down menu of pages ( as seen in the picture. Restarting, Logging off, Shutting Down is impossible.