Let your bf know he is being an inconsiderate asshole. If you really want to help your aunt and can help her then do it. And if your bf will break up with you that easily it sound like to me that he is looking for an excuse anyway. Your aunt if really sick, and will need the help of someone. My uncle has thoat cancer the let me tell you from experience treatment is tough on them. It will drain her completely. also something your bf should know is treatment has gotten alot stronger the past couple of years therefore it is harder on the body. That maybe why his gpa was able to do it on his own. Just trust your heart girl. I want to leave you with one thing to think about. If your aunt dies while doing chemo will you regret not going there and helping her. And if she survives will she ever reach out for your help again, or will she remember that you told her you wouldn't help when she needed you most.