Wow, sounds like your mom isn't understanding boundaries. It's a hard thing because I feel how you just want things to slide by but then it's like,....something inside telling you to tell her to mind her own business!! I don't think it matters what you tell her about the jobs. She isn't you, and she won't understand the situation you're in.
I guess just tell her what you think she'd like to hear, but I don't recommend letting an abusive relationship keep going. It's not good for you. I know it's your mom, but we don't pick our relatives. Maybe try to work on some personal boundaries for yourself? There is a good book called Boundaries by Dr. Henry Cloud. I think there are some Chrisitan references in it, but overall it's a great book. Best of luck in whatever you decide.