Okay, let me be a nitpicky a*** first: Rae's symptoms are crystal clear almost since the beginning, it kinda doesn't make sense it took the doctors (even if it's not the particular specialist) to figure it out.
But then again, it's clearly the message is about the invisibility of the illness. The distrust you got from medical professionals and friends, the depression after feeling like a burden and losing control of your life, accidentally pushing people away, and so on. I can relate to that 100% (I have the illness that isn't exactly the same, but comes from the same place). I got teared up after Rae finally received her diagnosis but then realized the aftermath of "managing the disease". Illness like that does seem to shut down the doors to your dreams, but you just have to find a new path around it, probably even opening to another new doors.
I read that this is based from one of the developer's story, I hope a total wellness and happiness to whoever that may be. This is an amazing story and amazing game, thank you so much for creating this.