Broken

My dad has stage four lung cancer and the doctors says he has 12-14 months. I begged my mom to tell me why they said. I love my dad so much and I know God can heal him and I understand it might not b who’s plan. I feel like I had to tell someone. It’s so hard. I want him to see my go to prom,graduate,get married,meet my grandchildren and all that. And my mom is going to have to handle seven children (one lives with my grandma). But I’m sad because I love my dad so much. Please pray/offer support I really need it. Thank you