Why is my little brother being so unresponsive , he is acting like a puppet , like wtf?

We attended a Funeral a week ago and this was his first and he's 15. One of my cousins broke his neck skate boarding and cracked his skull , trying to do the trick where the guys slide down a railing and my little brother Gavin witnessed it. Now my brothers acts like theirs something wrong with him , he sits around the house moping, he's pink around the eyes , he's snowy white in the summer , every sec he's vomiting, if you ask him a question he cries if the person asking gets frustrated because he wont answer or he'll mumble half of the word, he just radomly cries constantly. I'm getting angry because I'm 17 and want to enjoy my summer but since he wants to act emo , i have to babysit him while my mom's at work. His girlfriend comes over everyday and he won't even talk to her , he'll just cry whenever she hugs him and try to cheer him up. My mom doesn't want him to see a tharurapist because she thinks he'll get over it soon. He spent most of his time at the skatepark , he'd get a few bruises every now and then but I doubt if he'll ever skate again. What should my family do about this kid ? He won't budge!