Hi, I'm Nathan.
Sorry to hear that you're having trouble with this but I'll do my best to help you.
As a starting point, we'll need to reset the Firetv system:
Power off the tv and disconnect both power and hdmi from the Firetv.
Remove the batteries from the Firetv remote
Wait 5 minutes,
reconnect hdmi, then plug the Firetv power back in (using only the firetv wall adapter, not the tv usb)
put in a new set of fresh batteries into the Firetv remote
power the tv on, and make sure the tv is set to the right input to match where the firetv is connected (hdmi1, hdmi2, etc)
when you see the Firetv logo show on screen, press and hold the PLAY button on the Firetv remote for 15 seconds.
Let me know the results.