I'm tired.

So, me and the SO, are having to put our life on hold, because we have to take care of his momma. Don't get me wrong, I love his momma, I don't mind taking care of her. It's just that, her lazy ass husband won't do ANYTHING to help her, he cusses at her and yells at her. His brother won't help, just because he "has a life" he says, but can still come over and grab whatever he wants from her house, stuff we spend OUR money on. My SO and I can't get a break without anyone complaining, we can't leave the house long enough to do anything because she's in constant need. She can't fend for herself because she got both legs amputated. We cannot live our lives because no one wants to step in and help, we can't get even plan to start a family like we want.. I am in dire need of change. And I have no idea how. Any advice?