I don't have my own apartment. I'm only here definitively for six months. I decided to rent a room. To fighters. They fight a lot. They have two kids. I know that it's none of my business, but it reminds me so much of being a kid that sometimes it's hard not to block the battles out.
What do you do to stop the situation from escalating? Do I have any right to say anything? Is it stupid to care?
You always have a right to say something. Communication is the key. Here's the letter to send:
"Could you please keep your fighting down? I'm on medication for traumatic episodes during my childhood, and when I hear you through the walls it all comes back and I have to take pills that I can't really afford unless I work the streets."
Are you renting in their house or are they tennants too?
If you rent from them then STFU or risk losing your room, if they are tennants too then ask them to please keep it down because the walls are thin. Alternatively, when the start going at it, turn on your stereo and shoot the volume up loud enough for them to hear, they'll begin getting the message when every time they fight they have to do it with a soundtrack.