Why does my mum let her anger and frustration out on me?

my mom is exactly the same with me, its so stressful the only thing i can do is ignore her. it really agrivates me and iv tried to talk aswell, im actually quite worried about her because this morning i heard her murmuring from her room '"iv had enough i just want to die now" it actually really upset me knowing she could even think about that when she has a whole family who love her. no matter what i do to help her she still has something to shout about so i tend to sit in my room on my laptop all night now to avoid her, the only times i really see her is when i get my dinner and in the mornings, id like help also ): x