Hello
@Sophieprotected and welcome to this friendly and supportive forum. There is a lot of shared experience of dementia to be found here, so I am glad you have found us.
I am so sorry to read of your Dad's Alzheimer's and the progression of it. I've had personal experience of it with my Mum, (now passed away) so I know how horrible and painful it is to see them be slowly stripped away, bit by bit, of their normal self, by this horrible disease. I do feel for you.
Do you live nearby, which makes visiting him easier? Does he have carer's come in at all to assist with personal care etc.?
No, it most certainly is not selfish of you to feel the way you do. Please try to put that thought out of your mind. I am sure you are doing your absolute best for your Dad,; you have nothing to feel guilty about.
I'm sure forgetting your name today has caused you extreme upset and pain. Of course it will; it wouldn't be natural if you didn't feel like that. But yes, your emotions are in such a tangle and you really can't separate them out-- that's natural too.
Please so have a good look round the forums , and I'm sure others will be along shortly with suggestions and advice. Take care