I had a stroke about a year ago and I hope I can ease your worries a little. I can tell you 100% that your emotions change right after a stroke. Crying is very common. I can tell you that I had about a 6 month time right after my stroke that I cried at least one time everyday, mosts days several times. You have to understand that some of this crying is not all of time emotional. Sometimes crying is like a reflex is the best way I can describe it. There is a trauma that happened to his brain. When you have a stroke the area affected is dead, but the brain is an amazing organ. It starts immediately re-wiring itself around the dead part to heal itself. While this is happening all kinds of emotions come out because his brain is literally re-inventing itself and some wires might get crossed while all of this is happening.
As far as crying goes, just let him cry. It is part of the healing process from a stroke. I finally got my wife to understand that, because she was so worried, and I told her, "I just feel like crying, it is not a bad thing, I can't help it." He is only one week from his stroke. I am sure he is confused and afraid and doesn't want to admit it. This is normal. I too did not want to see anybody at all for a long time. Right now he needs patience and understanding. He may seem different to you and the truth is he is different. His brain has been altered but do not worry. He will recover, but it is a very long time and is different for every person. Give him some space if he needs it, he has to figure some of these things on his own. And please let time for yourself and get away if you need to. It is as hard to the loved ones as it is for the stroke survivor. Your father will be fine. I can honestly say that I feel blessed that I had a stroke. I would have never thought that right after my stroke, but now I can say that. The stroke made me think different about things and it is all good.
I can say that one thing that really helped me in my recovery was talking to other stroke survivors that have been there. I would be glad to talk to your dad if he has any questions and let him know that he is not alone.