My button control working in reverse
This behavior is expected: INPUT_PULLUP means the pin is pulled up via the internal pull up, i.e. it will read as high if not connected externally. 

With your push button you connect it to ground (0 volts), thus bringing it to low level and it will read as low. Therefore, in your code, you need to check for low level (LOW) to check if the button is pressed (as you found out by changing the code).