Master Alphonse couldn't be able to embrace the pain inside him. What he did is vomiting blood. His internal organs contained the hatred and anger towards himself, as well as the regret that caused him not to know all that time.
But he analyzed himself, and realized that even if he knew, the fact that he misunderstood his wife would have damaged his judgment, and he would not pay attention to them, he would just say 'Oh, but that's over, they are completely fine now, aren't they?'
He would treat them the same way. He knows that...
After vomiting blood, he fainted, and the trio ran to him. One held him from falling straight to the ground, another called an ambulance, and the other gave him some air with a folder he had in his hand.
Vincent saw all this and realized that he had no feeling of appreciation or concern for his father, and he thought about his mother.
