Hello!
I think it really depends on what schools you're looking at. While I was applying, I wanted to know my odds of getting accepted. Some schools were honest and said that they look heavily at GPA, especially your math grades. And others told me that since I showed an upward trend, they would consider that. Since you have a medical reason, you should definitely let the schools know. I have a friend who also had a medical reason for a lower GPA, and he got into a lot of schools.
So, my advice to you, is just apply to a wide range of different ranked schools and hope for the best! There are some programs that are more application based than theory. And anyone can correct me if I'm wrong- but I think more theory based programs look more heavily at your math grades . But as a affirmation, I don't think that you should completely lose hope of going to grad school.
And if you don't get into grad school this round, gain some work experience and then apply again . That seemed to have worked for a lot of my friends!
Best of luck.