Well, as long as you know it probably will be a difficult thing. Since you are sending the email regardless, you can remove the apologies. They mean nothing to her except show how anxious you are. Instead, put in a line that you are anxious about sending the email and leave it at that. You don't need to apologize or tell her "I know you said...". Also, maybe put in a line about how you think that you might need to find a new T if she is unwilling to be flexible on this issue.

This is no excuse for her behaviors, but I was thinking about it and there are possible personal reasons for it. But this is her stuff and not your and it shouldn't be getting in the way of proper treatment for you. But she may have been stalked or threatened in the past, causing her to have the boundaries she does now. Or she may have been taught in school that any pushing of very strict boundaries is considered "resistance" and must be strongly opposed. Again, this is her stuff that she needs to work out and it shouldn't be interfering with what is best for you. But if it helps you understand her more, that's a good thing.