I'm sorry you're having this issue with your Fire TV Stick. Try plugging it into a different HDMI port if you have one available. Also try disabling CEC (consumer electronics control) in your TV settings. It may have different names depending on manufacturer - such as HDMI-CEC, EasyLink, Anynet, etc. Check with your TV manufacturer if you're having trouble finding this setting.
I hope one of those steps does the trick! Let us know how it goes