I'm also sorry, Joe, and wish you and your family the best.
But I also agree with everyone else here: nicotine didn't make your dad any healthier.
Consider the fact that when life handed you shit, and you chose to shit in your hand some more AND THEN EAT IT. You could have chosen differently. Today, choose differently. Think about tomorrow only so that you are ready when life shits on you again.
Because it will. That's out of your control. What is in your control is (1) how you conduct yourself this moment (i.e., are you quit for today) and (2) how you respond when life shits on you (i.e., are you planning now for tomorrow's challenge).