Its just my bias, but whenever I hear of someone having extreme mood swings and aggression, the first thing I think of is parasites and/or a fungal infection and maybe some mercury poisening thrown in. Has she been on psych meds for her depression? If so, she's likely to have some issues with digestion and elimination which usually end up causing fungal and parastical infestation. Maybe you guys together can do some cleansing routines which are detailed here on Curezone. I'm sure it will help her Depression too, and that might be a way of introducing the idea to her.
Don't forget to take care of yourself. Its really not good for the kids and you to be in this situation. I would definitely talk to a counsellor about this if you are able. Good luck.