if 2 people wantd to marry and they were on disibilitycould they loose everything

I'm not sure why you think you would loose everything.  Disability is based on your work history and your own disability.  It is not needs based - meaning you don't have to have a very low income to qualify for disability.  Even someone who is very wealthy can apply for and receive disability if they are medically unable to work.  If n addition to disability you receive some needs based benefit. like Medicaid, or SSI, then those benefits might be reduced if you were to combine incomes.  However, you would then be looking at the income levels for a two person household instead of just one.