FBI's name check is like a black hole, nobody knows how long it will take to get your name cleared by FBI. Your name must be a very popular one. You may need to hire a lawyer to clear the FBI mess if the citizenship issue is affecting your career and family life. Somebody posted here a couple weeks ago, saying he waited for 23 months before his name was cleared by FBI.
One way to get senator "excited" about your case is to find somebody who is the senator's buddies. If the buddy calls senator's office, that will get the attention from the office. But I do not know how much the senator can affect FBI's action.
Good luck.