I would try not to confuse the deep discussions you had that were so meaningful to you with the remembering of them. They are not a package, all neatly boxed up as "the meds/seeing a psychiatrist issue" that your therapist mislaid. Your T was there, with you, 100% during each of those discussions and that is what you get, her attendance, then.

But she probably has 20+ people she sees, many seeing this or that doctor for this or that problem and the going-to-the-doctor memory of X, Y, and Z client of hers are just "facts", like who she has appointments with and the time; taking her calendar personally if she were in a rush and forgot to write in yours or double booked, etc. would be the same sort of mistake. She hasn't forgotten YOU, she has forgotten a fact in her own life, a who-is-seeing-which-doctor-for-which-reason.

I would imagine some of the forgetting was because you have not seen the psychiatrist yet and the two of you have not discussed him and how you feel on X med and whether it appears to be helping or not; think about that you have been discussing "might-be," which is kind of a worry/anxiety/future (which we can't know) subject so not easy to keep hold of for another? What is important from your point of view is not how it looks from another's point of view; our anxiety over future possibilities is important to our therapists but can be hard for them to keep hold of because they live in "now".