skysblue, I've missed you the last while! I'm sorry you've been feeling so low ... that would be hard, and contemplating taking meds is not an easy thing either.
All things considered, I think your situation and how you've been feeling has magnified your perception of the incident as well as your reaction to it. It feels bigger to you because you feel lower than usual ....
Things happen, people do forget .... or have lapses, brain farts. Happened to me the other day in an intense conversation with a friend, about a situation that occurred with another friend (and her concern relating to me not taking my meds when something fairly drastic happened with this other friend of ours when he quit taking his meds and so her fear over me not taking mine is painful for her....). At one point, I thought the conversation had shifted down a different track, so when she referred back to the man's wife/kids without using their names, I was thinking who?, and said, who? She was not pleased and I felt momentarily stupid for not keeping the connection made in my head - but it was because I thought she had shifted onto a different topic, so I shifted too, but she hadn't. I didn't forget, but I did lose focus for a moment. And I think perhaps it is that your T didn't so much forget, as she lost focus for a moment, and spoke before it came back to her ..... just a lapse, a crack in her concentration, as it were.
You keep saying you don't want to bring it back up, or beat her over the head with it. It wouldn't be that at all. This isn't about her .... it's about you and your feelings about this. She wouldn't feel as if she were being beat over the head about it!
Moments like these come up in relationships a lot, really. Someone makes a mistake, realizes it, apologizes, but maybe you still have lingering feelings. It's OK and good to talk about those feelings with that person - to say, I know you feel badly about what happened and I accept your apologies, but I still have feelings about it I need to talk about. Can you help me work through them? This is what you need to do with T. If you don't, this is where the rupture will actually happen. I wouldn't term this as a rupture right now exactly, but if you try to push these feelings away, not be open with her about them, and they continue to affect you, that is what will create the distance and therefore the rupture between you.
Don't hide from your own feelings, either ..... they are what they are and nothing to be ashamed of, just something to be felt and dealt with.
Your T is very good; let her help you with this. It's OK.