Mesothelioma diagnosis'

My husband has been diagnosed with malignant mesothelioma and our lives have changed dramatically. All he wants to do is get things done at home so he doesn't ‘ leave me with anything’.  The only thing is he is struggling to breathe when he tries to do jobs he has always done in the past and is reluctant to let anyone help him. How do I convince him that none of it matters, spending time together is more important.