Thank you both for the advice.
It seems so easy to just tell the Doctor, but when you've never mentioned it to anyone before, actually telling someone, particularly someone you've known (albeit in a doctor/patient way) for many years, becomes genuinely terrifying.
I'm planning on going to the Doctor's on Tuesday morning, and I do intend on mentioning it. I think I've put it off for so long because of not wanting SRS. I think, in my mind, I'd decided that the Doctor's would only respond to someone who wanted to actually have surgery. I think I've been frightened that I might get laughed at, as it might appear that my dysphoria, at this time, is a purely cosmetic issue. I feel the need to appear and pass as female, including voice, without the need to change my body. But the more I read the more it seems that is still a Trans issue, and that it does count as dysphoria.
I don't suppose anyone knows what a Doctor might say to me, once I tell them how I'm feeling?