Does anyone know if I have any legal rights against my siblings for failing to help with taking care of their mother? I have to pay for things just to keep us afloat, and my siblings are both wealthy. Now that I've lost my job, I don't know how we are going to survive. My siblings are both rich. How can this be legal? Do I have any rights?
You would need a really good lawyer, and if they are wealthy, they can likely out lawyer you. Sorry, it is impractical for poor people to sue rich people, unless they can get a hot shot, top notch, pro bono lawyer.
Suing is the most adversarial path you could take and you are unlikely to succeed.
If that doesn't get you anywhere, at least you'll have tried. And at least you'll have the facts down in black and white, which will clarify matters when it comes to seeking professional advice.
You do have one important right, by the way, one which is already being cheerfully exercised by your scapegrace siblings. You have the right to decline to provide care for your mother. As food for thought, what would your mother's options be if you were not in the picture? If you don't know, you'd better find out, because she may need them.