Is it normal that talking to my dad makes me depressed?

My father had a stroke about a month ago and is currently at home, resting and off from work. He woke up from the night before with the stroke, so he didn't realize anything was off until his job sent him home and we took him to the hospital. The stroke left him with some memory loss, confusion, and a slight speech impediment that seems nearly gone by now.

I'm so happy and grateful that he didn't die and with time, will be able to make a recovery. He's starting to talk more, but every conversation I have with him makes me want to burst out in tears. He keeps asking me where I work and about school, all questions he usually has the answers to, but can't remember. It's like talking to a five year old. He gets tired after our conversations and tends to fall asleep quickly, but during them, I'm patient and always end it with "I love you," because I get scared that he won't wake up sometimes and that's the last thing I want him to know.

My father is a highly intelligent person. Before the stroke, he would spend his free time reading thick tomes and researching different things ranging from a variety of topics. Our old discussions would last hours and his was just so... I don't know. I'm only 20 and I still have a lot to learn and knowing that I may not get that... get the true father-daughter experience.

And... it just hurts. I miss my dad.