Yes, I agree with other posters here that what she has and is doing is very toxic and also verbally and emotionally abusive. I also agree that you can get your siblings to help out so as not to carry the burden all by yourself. Also, it is not your job to keep her happy. I understand this may be a defense tactic to probably avoid her abuse, but you're right in identifying that it is not healthy for you.

I think your best bet is to free yourself and live on your own again, away from your mom. You can still visit her once in a while to help out, but you don't have to live under the same roof. This will be best for you and healthiest for you all around, as you learned being on your own at uni. And good for you for having escaped and for sticking to your guns about that!

You clearly have a good handle on how her behavior impacts you negatively and how that is internalized. Now you just need to escape again!!! Here's to your mental health and happiness. Be well. (((((((hugs)))))))