Realistically;
- Do you and your brother have a history of similar spats, but none have blown up as much as this?
- Is there any resentment bubbling under either way between you?
- How is home life at the moment?(doesn't sound good if this has happened)
- Is he physically larger than you, a more intimidating presence?
- Does he have a history of violence?
- Was the pillow throw the only form of provocation?
Do you really want to press charges on your younger brother, for one instance of anger, where you should really be talking to him about this? Does he show any form of penitence? What do you hope to gain from pressing charges?
You are both in and around your 30s for fuck sake, how has the situation come to this if not for a history of bad behaviour on his part that didn't warrant some intervention prior to this?