Why will remote no longer operate channels?

Been having several problems with my fire stick the past few months. First would not work properly with one of the apps . This is the latest one. My fires stick after using it for years has now decided on its own to scroll whenever I want to move left, right, up or down, I cannot make any selection except the first one or last one. It will not move one space at a time but instead moves rapidly to the end of the line of movie selections etc. I tried to reboot the whole thing but cannot enter my password to connect again to the network, because of this rapidly scrolling action. It is effectively not working.