Car Accident

I lost my baby brother to a terrible car accident almost a year ago (6 June 2018). My baby brother fell asleep at the wheel on his way home from work (in the early morning hour). He lost control of the wheel trying to correct himself and unfortunately ran into a building. No one else was hurt but it cost my baby brother his life, he was 34years old at the time. He left behind one beautiful little girl(5 years old) and his wife of 7 years.
My baby brother and I have always been close and my life hasn't been the same without him in it. Its been almost a year and I still haven't dealt with losing him. My other brother has been a basket case since we buried my baby brother. His wife (widow) isn't grieving very well, she is still suck on anger, and my niece is acting out because she doesn't know how to deal with all her feelings.
I've been the back bone in the family since my baby brother passed away that I haven't had time to grieve for my loss. I'm still trying to help my sister-in-law through her pain but I feel as if I'm being lied to since I recently found out that CPS has stepped in and removed my niece from her mothers care due to drug use. And was arrested today for public intoxication. I know that I can't help someone who doesn't want the help but its hard to watch the ones that I love self destruct. My brother isn't handling this well either and seems to be placing blame on everyone else. Right now, I just feel so loss.