Hi and welcome. Unfortunately, just stopping ADs like that is straight away likely to cause mental health to deteriorate, which won't be making things any better for you right now. I understand you don't want to betray your mum's trust but, where it's in her best interests, I think you may have to. And you shouldn't have to bear this burden alone ....

I don't feel that depression is an excuse to treat your family poorly, hunni, and this whole situation seems to be greatly harming your family. I hope and pray you can reconcile with your sister