I just want to visit with you re your post.
Your Grandmother is 86.
When Alzheimer’s disrupts memory, language, thinking and reasoning, these effects are referred to as “cognitive symptoms” of the disease. The term “behavioral and psychiatric symptoms” describes a large group of additional symptoms that occur to at least some degree in many, but by no means all, individuals with Alzheimer’s.
In early stages of the disease, people may experience personality changes such as irritability, anxiety or depression. In later stages, other symptoms may occur, including sleep disturbances; agitation (physical or verbal outbursts, general emotional distress, restlessness, pacing, shredding paper or tissues, yelling); delusions (firmly held belief in things that are not real); or hallucinations (seeing, hearing or feeling things that are not there).
Many individuals with Alzheimer’s and their families find behavioral and psychiatric symptoms to be the most challenging and distressing effects of the disease.
Now re your post, your attitude appears to be that your anxiety is all your Grandmother's fault as she is causing you to feel anxious yet you chose to live with her.
You also had problems with your therapist, you posted "You felt attacked".
I am sorry but IMHO it appears you have your own problems and you need to learn to accept you have anxiety and to deal with it. We have lots of great people with anxiety on the forum. Rewrite your post to tell us what your anxieties are, why you did not choose to live with your Mother and what happens when you finish school?
Your Grandmother has provided you with a place to live and at 86 yes she is going to be on opposite ends of the scale as you are 2 generations apart. She also owns the home and is sharing with you. Please treat her with respect.
I agree 100%, there is no such thing as selective Alzheimers.
My 2 cents, you need to move out and give your Grandmother back her home. How about the Aunt that took her to the doctors, could you stay with her?