How do I vent to someone whose life is hell without feeling selfish

Sorry if this is the wrong sub.

Basically I have one good friend and their life is awful. Abusive home and all that.

Now, my parents are going through a really difficult time and I am not handling it well at all. But how do I go "I can't breathe my parents are fighting!" To someone whose father has probably tried to kill their mum within the last month...

I don't have anyone else to vent to and I feel like I'm going to give up if I don't get comfort from them but goodness it feels awful to ask them for attention when I know what their life looks like...