I'm so angry with everyone

Please let me bitch and moan for a second. My blood pressure has been high for 3 days and not responding to the meds. My cardio told me to go to the ER if that happens. So I did. I run my own business and it's a one woman show. I state this clearly on my website.

I have a B2B client so as soon as I had to be in the ER, I informed her that I won't be able to fulfill her order. She asked immediately if I don't have a back up plan. I know in heart of my hearts that it's a legitimate question but it rubbed me the wrong way in that moment. We're in Europe so when people are sick, they're sick. When they're off work, they're off work. Nobody else would have received this question. Plus the person who asks that has 3 children, works behind a desk while I work on my feet all day. And to make matters worse, a week ago she called me to tell me that they won't be placing any orders throughout the August because simply there won't be anyone to place them since they will be on vacations. So, how is her vacation is a valid reason for her to stop offering a service completely but she can't understand that I'm sick and can't take care of her order? I'm thinking even if I had a back up plan, I was in no shape or form to activate it in my state last night. I really don't think people like this worth time of day to take on as clients.