Look up discrimination laws for your state. See if there is anyone who can advocate/mediate for you. They may have lawyers who can work pro bono as well.
Bullying is not illegal unfortunately. Most states are fire at will, which means they can fire you for anything. But they are not allowed to do it due to protected class, such as your disability. Most lawyers will try not not help you actually because it's hard to fight discrimination. Were there anytimes that anything was said about your disability and were reasonable accomodations made? Explain the thing about the spill and how you did not see it, and how management would not take into account your visual impairment before writing you up. That sounds like discrimination to me.