I agree with keeping some distance.

We have issues with my husband's side- his sisters and his parents. And like you, we are the only ones who have it together and never ask for anything. However, this creates resentment for some reason I cannot wrap my head around. His sisters assume we have our position in life because his parents help us financially (not true!) and his parents are resentful because we don't need thier help with anything. Wierd huh?

Last year we had a run in with my SIL, she has been saying and doing things, and making trouble for years. Finally it culminated into a huge blowup and we asked her to please just not contact us anymore. She has tried several times- sending nasty letters, calls, other things that are odd and I won't get into. Anyway, it's been a good year since we have stepped back from the drama. I am sorry whatever her issues are, but we don't need to subject ourselves to the constant jealousy and fighting and bad feelings she has.

I know it's different because this is your mom, not an inlaw, but I agree put some space between for a while. Maybe then you can discuss the issues with her once a little time has passed. I'm really sorry but hang in there- you aren't alone in these issues.