This is perfectly normal @Definance, like the others said. Do you know which form of Alzheimer you were diagnosed with? If it's FTD (fronto temporal dementia) , it's normal to experience some mild cognitive dissonance, which can lead to emotional confrontation with loved ones or people close to you.
I would recommend laying the cards on the table with your support network. Explain how you feel to them. Tell them the truth. Too many times, loved ones do not understand what's happening due to a lack of education and cliches perpetuated by books and movies. But this is real life - your life.
Best of luck, and keep us updated, please. There's a lot that you can do to minimize the impact of these mood swings. I am NOT a doctor, so I cannot and would never diagnose you or recommend medicine online. But a good GP will have access to certain medications that can significantly help; for example, please consider asking your doctor about SSRIs. They helped my mother, and the mood swings disappeared. This, again, is purely a suggestion. Only a doctor can make that assessment.