I Am Angry

So, I was at the hospital in the ICU to visit my grandmother who has maybe 2 days to 2 weeks left. I'm there with my father (we are more like a team because I co-parent his other children) and we are all there, and he keeps leaving! After the third time, I go out in the hallway to ask him what he's up to, and OF COURSE he keeps leaving to smoke. While his mother is dying! We fight constantly about his smoking addiction and it just makes me so mad that he would do this at a time like this. We are getting a new apartment anyway that is smoke free, so he has to stop. I know he's going to regret leaving to smoke when he has no more time with his mother, but he's too blinded by the appeal of his goddamn cigarettes to give a fuck. I hate it so much. And I was venting to my fiance about it, and he says "oh, I smoked today" and I about lost my damn mind. I'm angry at my father about smoking and the only person that can comfort me pulls something like that at the most inappropriate time. It's ridiculous. Am I overreacting? What can I say to my father to get him to pull his shit together? And I know all the pro smoking people are going to blow up at me but idc whatever