"Cyndi said she got really sick because her body reacted to a certain medicine really badly. She said the only reason she was able to recover successfully was because of the advice she received from a pharmacist working at the drugstore she always goes to. She said she was really lucky because even her doctor couldn’t detect the cause. If she had kept taking the medicine, she would have died. "

Hello! I'm so sorry the passage above is really long, but could you please read it and tell me how I can make it sound natural? Thank you in advance.