I agree, my father a few weeks ago had a massive stroke, the 1st week it was touch and go at the hospital. Most stroke victims die within the 1st 7 days. I am luckier than you as my father is still alive and although paralyzed and unable to speak, he can understand everything I say to him. So I have told him more times now than ever before in my life how much I love him. I had to fly to Texas where my parents live to since I have power of attorney, my father's thinking is I understand medical terms and procedures much better than my mother does. In his safe deposit box besides the power of attorney was his last will and testament, on it I caught a glimsp of it that read "My beloved son Börger shall be executor of this last will and testament" etc. So your parents know how you feel without ever telling them, after all they know their kids.
My heart goes out to you that you didn't have chance to tell him how you felt, but trust me he knew, he's always known.
I have moved my father to Delaware with me because Delaware has one of the best stroke rehabs on the east coast so he is there for short term therapy of 2 - 3 months, hopefully after, he will be able to return home. I will say this, I've seen some sights in that hospital with all types of people, which has humbled me in more ways than I can count. I've seen just how fast a person's life can change for the worst and how little things that other people do to help, can make a world of difference in their recovery. I've also learned to treat others as if it would be the last time you ever see them, because you never know, that just might be the case.
Keep your chin up K.C. and go one with your life, it will get easier as time goes on. After all isn't that what your father would really want you to do?
Peace K.C., I wish you well.