PunkDizzle,
I'm so sorry you're going through this - it is a horrible disease for anyone to have or have to watch someone struggle with. My mother had it for almost ten years before she passed in 2005. My sister has it, too (she is only 57). It's so hard because you end up losing someone you love twice - while they are still here with us and then again when they pass.
The first time my mother didn't remember me was heartbreaking. You Dad needs lots of love and most of all patience. I remember my Dad arguing with my mother because she thought he had not closed the garage door. I finally told him to just go and pretend to close the door and she would be fine. He did - and she was - and totally forgot about the incident three minutes later.
My sister is in bad shape right now - I posted in the MS Social Chat about her. It never gets any easier to watch loved ones suffer. I'll keep you and your Dad in my prayers - your Mom, too, because she's got a hard job right now.