You know... I told my sister that I thought about not moving out when I finally finished highschool... and she said something to me. She told me that I need to live my own life, and I can't live it for my parents. I know you feel the guilt, and I'm not telling you to completely ignore your mother. But if you can't do it, you can't do it. Why drop everything in your life, and make ~yourself~ miserable to correct ~her~ mistakes. Why do ~you~ have to be the one that suffers from her choices, or from her inability to hold a job.
Of course... she's your mother, right? If you can help her out, then do so, and tell her that you will help her when you can. But you also have to let her know that you now have your ~own~ responsibilities in life, and you can't customize your life to revolve around her needs.
So try and talk to her... she may get angry, but that's her choice. Be happy in your life... live for youself, and do what you need to do... and if you can spare some time to help her out, then do so. But don't put yourself at a disadvantage just to correct ~her~ mistakes.
I know it may sound harsh, but I'm sure you'll understand what I mean. You can't help but love your family, and you would do ANYTHING to help them... but there are some things that we have to continue doing for ourselves. Your mom is like this most likely due to her errors... so while you can help her out, you don't have to destroy yourself to correct ~her~ mistake. Does that make sense...? Find a happy medium, something that you can make it work out for. Remember, family will ALWAYS be family... they ARE important, but if you can't do it, then you can't do it.
Maybe having a chat with her will help you out. Seeing what she needs, and if you can help her with that. Maybe discussing something and making a plan will help clear up the situation more :). Good luck!