Forum:Quest Line Stuck

Ok so heres my problem, i have already beat the game and i had saved before started the last fight at hoover dam so that i can reload and continue playing untill new content comes out. well i was working for mr.house. but i reloaded and started doing a lot for the NCR. now i have a quest identical to the one Mr.house would give you to prep for the last mission. well since i had already once seen/protected the president i cant re-do it so therefore im stuck in a quest i cant finish because i have already done it for Mr.House...and i dont know what to do...with out the option of restarting. cause that would suck. >.<