Rumors only, but I've heard that Brownstein doesn't always require a letter, and I've heard that Meltzer doesn't require a letter if you've already changed your gender marker on your drivers license.
And I've never heard of a surgeon who requires two letters for top surgery. This is not to say that it never happens, but I've sure never heard of it. Are you sure your therapist knows what she is doing?
If I were you, I would consider a new therapist. And definitely start sending out e-mails to any surgeons you are considering. Apart from the letter(s), how close are you (emotionally, physically, financially) to getting top surgery?