I am my mother's caregiver who has glaucoma. I just found out that I have Glaucoma! How do I cope with out telling her?

I am my Mother's Caregiver. She is 88 years old and has Glaucoma. She's blind in 1 eye and has about 40% vision in the other eye. I just found out that I have Glaucoma! My Husband and I both decided not to tell my Mother about my situation because I don't want to upset her. I'm trying to keep my emotions under control, but I have a tendency to retreat when I am overwhelmed. I am already taking medication for anxiety and depression and they have helped tremendously, but I'm getting nervous. I'm just nervous.