@sara96, I can see that you are very worried about your friend. You are a good friend. There are treatments available for relapsed Hodgkin's lymphoma. Here's some information https://www.lymphoma.org/understanding-lymphoma/aboutlymphoma/hl/relapsedhl/

I think she is scared and that may be why she reacts agressively. Would it help to acknowledge your fear and her fear? Could you start simply, but saying "I know you're scared. I am too."? Then just listen first. Do you think that might work?