All of the above are great suggestions. I think the one to start with small steps is what I would recommend. It will not be easy and you certainly will need to enlist your parents aid at some point. I would also suggest that you begin to take control of your life by sitting down with your mother and explain in as non-threatening a way as you can the issues with the way you are currently using the attendants. She may respond more to that than "I am working towards moving out".

As far as finding attendants, some other places to try are churches, nursing schools and vocational tech programs. No guarantees, but worth the try.