​beginner writer needs help writing chronic illness!

Hello! I’d like to start by saying that I do NOT know if this is the right sub to put this in, and if it’s not, please tell me where to ask my questions!!! So, onto the main subject… I like to give representation to minorities with my oc’s, and I thought that this would give more depth to one of my already existing characters. (English isnt my first language, I really hope I am not being disrespectful about this, please forgive me if I’m acting insensitive!!!) One of her traits is that she used to get sick EVERYDAY. She would get a fever and vomiting almost every day a week. She got help later on, having the possibility to see a doctor (which she couldnt before.) She still got sick pretty often, but it was way more “bearable” now. So!!! I thought about giving her a autoimmune disease, weakening the immune system. But I realized by reading things on the internet that this was super confusing and I didnt now which one would be appropriate and how to write it without sounding disrespectful, insensitive or offensive!!! I really really need some help here, from people who know medecine or people with that type of illness. Please! Help me out!