metroid prime - i used a fuel cell in the wrong room in valhalla. i cant find any more, do i have to start ove

i cant remove the fuel cells from the wall now. i saved my game already, i think im screwed

Valhalla actually doesn't seem to do much. Just ignore it and do everything else until you gather all the fuel cells. There's plenty of them in the game, no such thing as using it in the wrong room.