(1) Use a phone. Email has nigh on zero impact. Trust me on this. Letter mail gets read, but you don’t have time. Reach the House switchboard at (202) 224-3121 .
(2) Remember, this person works for you. You pay his or her salary and you voted for them. You’re the boss here, or at least one of them, and it’s they who should worry about what you think of them.
(3) Identify your name and the town or neighborhood where you live. If you are not a constituent, save your phone bill and yell at the TV.
This is urgent. Call your Rep today.
More tips here.
And hearing that the Speaker thinks she doesn't have the votes makes calling your rep, and telling them how you want them to vote, more urgent, not less.