That's rough
Alzheimer's is a incredibly brutal disease that causes terrible suffering. While that may sound negative I think it is important for you to prepare yourself for what lies ahead. Watching members of my family get taken by the disease is some of the hardest experiences I've ever had to endure in my life.
One bit of advise: Be to be mindful of frustration and anger. Those emotions tend to surface in both loved ones and victims as the disease progresses due to the fact that they are a result of fear.