Emailing sounds like a good idea that way t can bring it up instead of you trying to remember.
this strikes me as something important to you from reading your post and you have said a few times that your ED is not severe but it IS important. Sometimes its hard to bring up all of the things we plan to bring into therapy on any given week but as this has been playing on your mind ever since and you have noticed a pattern, then it is important and should be talked about when you are ready.