Windows? And you're trying to use the context menu on the menu bar?
Yeah, that broke in 14.2. We're working on it.
Is there a way to go back to an older version of Photoshop CC so that I don't have this problem for now? It is like trying to drive a car without a gas pedal.
No, there is no simple way to go to an older version.
But you can stil change the units by typing them in the options bar.