Increase SSI Amount- Living Arrangement?

I've been getting $486 a month on SSI since I live at home with my parents. I know they increase to the $733 if you pay your fair share. What does that mean?

I pay $200 a month for my food,essentials. I pay $100 for the electric. With my back pay, i redid the whole basement, and I'm still 'renovating' , It cost over 10k so far. I cannot move anywhere else due to even rent costs, so i have to live with my parents.

I cannot afford even a crap car plus insurace on $150 a month. So im forced to rely on my parents. And my parents hate it since i cannot even afford to pay 'rent'!

Can i get an increase to the $733?
What does Fair share mean? I heard someone say you add up all costs and divide it amongst the people living in the house.

So i'm supposed to be paying part of my parents mortgage, the rest of my familys groceries,electric, taxes, garbage, etc? Thats more than the $486 i get so how is that even possible?

I'm paying for all 'MY Stuff' so i'm lost.

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