I have a medical condition and was told I couldn't use the rest room at circle k and the restrooms were open and I went on myself

I'm sorry that happened to you.  Circle K is a grocery store?  I don't know of any law requiring them to let you use its bathroom.  However, I would suggest if you have a problem, you might consider wearing an adult diaper if you are going to be away from a bathroom.  Most elderly citizens have to wear diapers.