In denial

Vascular dementia has started and my partner lives in denial of it all.
He has some cognitive limits, often feels week and tired, has episodes where
he experiences numbness in limbs, his legs might buckle under him and his
speech is not as clear as it used to be. He will occasionally twist and use his
words wrong, often without noticing that he did so. For example: he asked
for a specific meal to be cooked, and what should have been 'steak and kidney
pudding' had come out of his mouth as 'steak and puddney kid' instead. He
was not sure that he had said it correctly, so asked me for clarification on it.
At least, this time he was somewhat aware that something had gone wrong.
But, often than not he will say the wrong word in a conversation when he
had meant something else altogether with it, without realizing the mistake.
Despite such happenings he seems to think that there is nothing wrong with
him at all. He can`t even realize that his aggressive behaviour at times is a
sign of his dementia. He convinced himself that all`s well and says that it is
me that has changed. He accuses me of treating him like a child, and wants
me to drop the 'condescending' act. Even when he says this the word itself
comes out twisted, but he has not noticed it himself. I don`t try to correct
him on this as it would spark another argument and aggressive flair-up.
I`m not sure at the moment how to tackle this problem and hope to be able
to discuss matters with our GP at the next appointment. My partner has to
be persuaded to accept the fact that he has dementia and assured that me
and the medical professions will do all that we can to help and care for him.
How to convince him that he truly has this disease is something I need to
find an answer to, as caring for him at home can be very frustrating and
stressful at times. He`s always telling everyone that he`s fine when in fact
he`s not, thus avoiding the issue of having to deal with reality. All I can
hope for is that with passing time things might get easier for both of us.