It seems you have a star of a husband. Hope it stays that way. He sounds a very mature and caring man.
I haven't been in your situation, and won't ever be. My mum had AD and was 80 when she went into a home, which had to be, and she died just 12 months later. I can only imagine if it were my dad. He would have said the same - put me in a home - and I wouldn't have done so. But actually, I know he would have meant it. He would rather that I enjoyed my life to the full, as he had done when he was that age, than spoil it for me. I know how you feel. I would have died rather that put my dad into a home, but thinking about it, he would probably rather have died than spoil my life, which is how he would have looked at it.
Anyway, love, you have decided that you will not do anything for a couple of years, becuase of your children's schooling. And your husband agrees with that. Make sure you take time to make your husband feel valued and special, cos he certainly is. Many other young men would resent your situation and be unable to cope. Yours is one in a million. But do try and organise periodic respite for your all, with your dad in a home for perhaps a month at a time. Twice a year, say. Then the pressure will be off you all for a set period. It will give you a much needed break and allow you to be a proper family for a time.
I do think you should be putting your needs and those of your husband higher on the list of priorities before long. I know how you feel about your dad, but you have a life to lead too.
Much luck and love
Margaret