I went on a course - "caring with confidence" I think it was - it went through a lot of important things, finances, stress management, etc etc. There are lots of people in the same boat, trying to keep the family close. It can be very difficult.
I suppose people have already said that you need to look after yourself. It is so easy to concentrate on your father and neglect yourself. But you will have to give up a lot.
Try to get out as much as possible with your dad if he is able. Memory cafes, day care centres for him, perhaps even the odd meal in a pub, a walk around the block. Anything to get you out, feeling 'normal'.
Try to make things as easy as you can. Don't feel you have to cook 3 course meals. I buy ready meals from a local butcher, wiltshire farm food/oakhouse are also good.
Sort out a dentist early on. If he cannot go to a dentist then there should be an 'emergency' dentistry scheme who can visit....sign up to that as soon as you can (it can takes months to get on the books, but once you are signed up they can visit within 24 to 48 hours if there is an emergency).
Get a podiatrist to keep toenails under control. I used to do my dads but always drew blood (even the podiatrist did once, to her mortification....he had funny 'quicks').
I never saw dad to 'the end'....he died suddenly of a undiagnosed blood clot. But he was getting a lot more stressful for me & time consuming as he declined near the end and his frailty impacted on his dementia. You may reach a point where you cannot cope (physically, mentally) and you will decide to seek alternatives....if you reach that point it wont be defeat, a person can only do so much.
But enjoy the good times....have a laugh with your dad. Long may it continue.