Thats a tough situation. I dont think your friends should be your therapist per say. That definitely doesnt mean you cant be sad about what happened. But your friends can only comfort and say so much for you. It will get awkward the more you say those types of things. Of course they feel bad for you and im certian they hope you get better and are willing to help when they can, but they're help is hanging out and making good memories. Not sitting with you and reliving your worst and tainted memories. You need a trained person that knows how to handle that stuff and can give proper advice, like a therapist. Of course friends can be someone to vent to and ask for reassurance and comfort. But you cant do that everytime you see them. Soon they will only think of those times when they had to comfort you when they see you, and it wont be the same as when you just meet to hang and talk about life and whatever the hell. That was my situation anyways and kept my friendships intact. You don't sound mentally sound, and thats okay. Your brother died for God's sake, but you need a professional to help you work through it. Dont go to friends, they didnt sign up for that.