The robot prime went into battle, blew a hole in the wall for me to get in, and is now in pieces. I keep gving the citadel cameras and modular sensors but the robot never gets fixed. Was this the end or am I missing something.

I believe they say "someday we hope to fix him." They will not fix him after he is destroyed no matter how many cameras and sensor modules you give them during the game. Maybe in the next game he will show up or something but not in Broken Steel. So yes it's over for now for Optimus Prime.

Also it's silly to think all it takes to fix him are a bunch of sensor modules and cameras.