I feel so sorry for you--I felt that way when my mum died, but her loss didn't really 'kick-in' fully til Dad died as well.
I still miss them both desperately--Friday evening was our 'Family Night'
I also wonder if I should have made mom go to hospital sooner---she was just 5 weeks from diagnosis to death and it was such a shock--secondary cancer of the bone and no known primary.
It WILL lessen, you'll never forget your dad--they are so special for us girls

but I'm sure he appreciated all your love and care for him and you must have inspired him to think he had a 'Fighting Chance'
Look after yourself, look into the possibility of comfort and counselling, and keep posting when you get down,
love Brenda