When you encounter someone who is being overly dramatic, what is the first thing you do to protect your peace?

Why do I cry so easily? I cry very easily when people get mad at me, start questioning me, or bring up something I don't want to talk about. Why do I cry so easy and how can I make myself stop?
How do I handle a situation where my mother-in-law needs a place to stay urgently but we have unresolved issues?