My mom has small cell lung cancer!?

My mom found out in january she had cancer and she has the extensive kind. What im wondering is does this kind make you act like a child and talk like a kid? They are saying she has only a certain amount of time unless if they find a cure, I don't like being there because it hurts me. I want too but its so hard im there everyday but 3 days out the week n the 3 days im off I leave to go to my finances house. I dk what im going to do if she passes, what can I do? How do I cope now? Im onky 20 and im trying to get my life on track. It hurts to think about it and some ppl in my family are getting mad at me b.c. im afraid to lose her n im not there those 3days.has Anyone else go through this? Please help?