Dear Cath
How sad that you are having this struggle and all you are trying to do is the best for your dad. But don't give up. Believe me, all of us on here have had similar problems at some stage in the journey.
We are all here to encourage you.
Going back to Brucie's response, there is no definition of Alzheimers or even of dementia. My mum knows me perfectly well, and my husband and daughters, but she definitely has Alzheimers. And actually it doesn't matter if your dad has got a "label" or not, his needs are his needs. Forgetfulness and repetition are symptoms of any over the age of about 55 (as most of us carers are!), but when they get to be a cause of possible danger, further investigations are needed, and perhaps more support is required.
I hope you get that appointment soon. Keep us posted, we are with you.
Kind regards
Margaret