Scared for my boyfriend:(?

My boyfriend has been experiencing alot of sadness recentally, and it seems to all be surounding people he really loves. The smallest thing will set him off and i'm worried about him, he's been crying alot recentally. I've been thinking its abandonment issues. His dad left him, his grandpa died, and his best friend was recentally shipped to rehab in the middle of the night. So i'm just worried about him and why he has been so depressed and crying lately. All of the events i stated above happened at least 6 months or more ago. He says he is afraid of losing me or his mother and is extremly over protective. I'm really starting to worry because he seems to be getting violent with himself when he is sad or crying. Most of the times he seems okay. but when he goes to bed at night he's up to 4 am crying. i just want to know if anyone could give me some advice or opinons on what this could be?:( thank you