Who should i start, ALL my RB's are not producing!?

Only starter i have is Frank Gore, and then i have a RB slot open and the rest is Marshawn Lynch (against the Pats, yikes!), Maurice Jones Drew ( i had a chance to get Mcgahee, boy was i dumb), De angelo Williams (Mr i dont get in the game till the 4 quarter), and Chester Taylor, hes injured! I'm in a running back chrisis. Should i trade Chad Johnson for like Joseph Addai? My other receivers are Larry Fitz, Santonio Holmes, Bennard Berrian, and pathetic Reggie Brown on the bench! What do i dooooooooooo?