Thanks everyone for the well wishes/condolences/hugs etc. Just got off the phone with my sister, my dad is gone. She said she knew he wasn't really there (before he actually died) because he had one eye partially open and almost never blinked. Kind of freaky. Also he apparently didn't look anything like himself, more like a random old person. Normally he was very striking and attractive for his age.
He died just 4 days before my mother's 11 year yahrzeit (death anniversary). The funeral is Thursday. So from now on both of their kaddushes will be said on the same day.