You need a HDMI Hub switcher (maybe with a 3 or 5 input with 1 HDMI output) to connect to your single TV HDMI port.
You will find plenty of HDMI hub switchers from places like Amazon, EBay etc, for about £10.
Wherever you buy the HDMI switcher from, make sure you get a no quibble returns policy if for some reason the HDMI switcher is not compatible with your TV and nowtv box / stick.
Look at something along these lines.
Hopefully someone who uses a HDMI switcher in their setup can recommended one for you with a link.