What to do about family fighting?

My mo, and grandma are constantly fighting over each of their "bitchy ness". They are constantly fighting over my brother and I being lazy…

First of. We aren't lazy we do what we can do to help. Whenever we sit down they go berserk saying how lazy we are. Like I'm sorry. You didn't ask for my help.

I'm honestly just getting tired of it and I'm really wrong. I've cried myself to sleep because I don't know what to do. Any suggestions? Please?
Added (1). My mom*
Added (2). My mom calls me lazy. When she comes home then up to her room for the rest of the day to play games on her iPad. I understand she works and all… But her job is pretty simple.

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