Cannot cancel iwatch workout app

the part of my screen which has the X on it does not register my finger push, which means my workout just goes on and on. Even if it is paused, when I flip my wrist to see the time, I get the workout app readout instead of my watchface. I have looked at the forums and tried killing the task by pressing the long button until I get the shutdown screen but it never kills the app and it still takes over my home screen. Very frustrated as I can't use my watch anymore. Can anyone tell me how to either get rid of the app (I don't need or want it), or, at the very least, make it dormant.